Are you empathic, misunderstood, telepathic, have a sense of an unworldly connection to someone else who you just haven't met?
Even if you are not feeling the above, you may be constantly searchng for your other half, have a deep sadness that you dont understand.  You may simply have a feeling of constant searching causing you to frequently pick up and move on, breaking hearts behind you.
Do you feel guilty constantly (for being alive ) and always feel that everyone else's needs and wants are more important than yours?  This is not necessarily low self esteem!
Do you feel duped, let down, things are not as you expected them to be?
Are you very interested in twins and their relationships and think everyone else is too?  (They are not).
Are there twins in your family?

You may be a womb twin survivor!
There are a number of ways that being a twin in the womb can effect your life depending on the  individual circumstances.  Other typical feelings may be:
Deep down, I feel alone, even when I am among friends
All my life I have felt restless and unsettled
Wherever I am, I scan the faces around me
I like to have plenty of personal space
I feel guilty if I succeed at anything or am better than someone else at something.

What is a Twinless Twin?
One in every ten births started out as multiple zygotes and ended in a single baby.  Statistics are only becoming available now with the miracle of ultrasound.  These statistics are changing though with the increase in IVF therapy where multiple zygotes are implanted into the womb.  Within the first trimester of pregnancy, it is common for the weaker foetus to die for a variety of reasons.  In the past the parents and doctors would not be aware there were multiples.  If this occurs within the first 2 months, the partially differentiated cells are absorbed by the twin or the mother.  DNA tests have shown that the remaining twin, having absorbed their sibling in the early stages of development, will contain the DNA of both themselves and the twin.  They are essentially a single twin, two people in one. 
If this death occurs after 3 months of development, the body, more fully developed becomes flattened and remains whole within the womb until birth.   They are born healthy and appear to all as a non--multiple birth but are likely to have some physical issues such as scoliosis and possibly some dermoid cysts  depending on the gestation at the time of absorbtion.  However spiritually, psychologically and emotionally, there is a profound effect on their lives.  

The Baby is Fully Conscious at Birth
Many people are not yet aware that an infant is fully conscious at birth. "In fact, it is known that moments after conception a human being is uniquely human in shape, position and structure (Blechschmidt 1977). In each stage of development whether it's an embryo, a foetus, a newborn, a child,  a human being is whole and complete. Even the young conceptus is conscious and capable of experiencing pain and pleasure. It has decision-making capacity even without a nervous system.  Yet, along the way the human embryo undergoes stress and trauma. We develop through certain specific stages, which have been well documented both in embryology and developmental psychology. Within these stages of development there are numerous specific differentiations that occur that give us our individual uniqueness and personality. 
However, when we experience stress, trauma or shock in any stage of life, but especially during the pre- and perinatal period, there can be devastating consequences to our health throughout the life span. This fact was reported on the cover of Time magazine in September of 1999." Michael Shea 

The Dream of the Womb (taken from http://www.altheahayton.com/wombtwin/articles)
Pre and perinatal psychotherapists maintain that experiences in the womb and around birth leave some kind of impression in the mind of the foetus that remains throughout life. (Chamberlain 2007) These impressions are timeless, for there is no sense of time or chronology in the womb. They are formless, for they are formed before cognitive functioning is fully developed. They are confused, because there is no context within which they can be understood. They cannot be described as "memories" exactly, so I have called this mix of vague impressions, feelings, beliefs and attitudes the "Dream of the Womb." It is my belief that the process of self understanding cannot be complete without some attempt to unravel the details of one's own particular Dream of the Womb. The re-enactment of a "foetal mode of being" in psychotherapy has already been described. (Ploye 2006)
Until these vague impressions are given some cognitive context, they can only be expressed non-verbally. Until this is understood, the psychology of the individual is driven by the need to keep the Dream alive. These impressions are acted out in relationship, in terms of one's sense of self, in various moods and feelings that are unrelated to the real situation, and in maladaptive behaviours. Only when the Dream is contextualised and fully interpreted in terms of a series of real events taking place in real time chronology, does the individual awaken from the Dream to the reality of their born life. This effect is particularly noticeable in the case of a "wombtwin survivor."

Relationship
When two or more embryos develop together in the womb, they are all being hard-wired for life in the presence of each other. This is how they can have some vague sense of one another, even in the earliest weeks of pregnancy. If you are a womb twin survivor, then the life and untimely death of your wombtwin is in your Dream of the Womb and constantly re-enacted in your life.
This imprint of Someone Else lies somewhere just below the lowest threshold of memory, but I do not believe that it has passed out of sight and out of mind for all time. I have evidence from wombtwin survivors themselves that the imprint is always held in mind. It is expressed in the body, mind and spirit of the survivor as a kind of lifelong, coded message. 
"The results of preliminary research seem to show that in the four areas of paradoxical beliefs, emotional discomfort, searching and self-isolation, there are significant psychological effects on the survivors of a twin or multiple pregnancy. It also seems that simply to discover the reality that lies behind these difficult feelings is therapeutic. Many of the psychological issues that were raised, such as self harm and relationship difficulties, are widely discussed. It is hoped that the possibility of being a wombtwin survivor may be taken into consideration more frequently by the professionals involved in providing therapy and treatment." A.M. Hayton (Feb 2005)
The concept of "empathetic failure" (Kohut 1966) is related to the twin- twin relationship, insofar as identical twins do seem to have an extremely empathic relationship with each other that is unspoken, and can border on the telepathic. (Kohl 2001) An identical twin would define empathetic failure as an extreme form of disappointment.  Empathetic failure is described by some clients as the primary cause of their depression. In this case it is invariably an intimately related figure - parent, sibling or sexual partner - who has failed to display a sufficient level of empathy and this has caused great pain to the client. If the pain is related to the loss of a twin - the one person who could provide that level of empathy - then this response would make perfect sense.

Moving forward
Through Craniosacral Therapy treatment and Spiritual Healing, embryonic experiences often come to the surface as a cause for significant physical, emotional and psychological conditions in ones life.  Even experiences of IVF babies whilst in the petrie dish have arisen as influencing factors.  This is a clear demonstration of the need to be aware of the spirit and physiology of the arriving child from very early age, especially in these days of increased reliance on IVF.  The Vanishing Twin syndrome/ Twinless twin/Wombtwin survivor is one that is especially relevant in that it has a major influence on the life of the surviving twin and effects all their relationships.
The biggest hurdle is overcome with the realisation that this has occurred to them and it usually makes sense to not only the individual but their friends and family as well.  They review their lifetime experiences which finally finally fit into place like a jigsaw puzzle.  There is a sense of having already known this on some other level.  Only after accepting this occurance can the grieving finally start.  This is a deep process that once again really cannot be understood by those that have not experienced this themselves.  
There are many forms of support via healing modalities that access this time period such as craniosacral therapy, akashic records, psychotherapy, rekindled ancient wisdom, kinesiology or hypnosis to mention a few.  The most important factor is the ability, space, time and support to grieve fully.  This is a loss of the closest possible relationship available as a human being which alone makes it profound, but there are also often soul factors and past life issues consolidating and confusing matters further.  Each layer of trauma needs to be accepted and allowed it's voice to enable the profound life changes that occur as a result of shifting this deeply subconscious trauma.  
For parents who are planning or expecting a child, craniosacral therapy is valuable for all stages of development, taking into account the conscious being even before conception.  For those experiencing a multiple baby pregnancy, craniosacral therapy throughout pregnancy and post birth can help support full development of all babies as well as provide a support for parents and child in the case that only one child carries on to develop fully.