Hi Annette,
I think you're going to find that this topic is a bit of a can of worms. Lots of strong opinions and no "official" position.
There is a growing belief in the field of medical research that there may be a physiological component that causes one to be born as transsexual. But as there is no medical test as of yet to check for this, it's not terribly helpful in answering your question about yourself.
I would simply say that if you feel like you truly are a woman, and that you are not truly a man despite what your body looks like, you're leaning more toward the transsexual side of things than not. This is especially true if your male body causes you mental & emotional distress, regardless of whether you have the opportunity to change it.
If you're pretty comfortable with your male body, but you still like to be perceived as a woman more or less permanently, you are in a rather poorly defined area when it comes to the current labels. But regardless, you'll have a lot in common with transsexuals in some areas.
If this topic is something you feel you need to know about yourself, therapy can be a great help. Are you seeing a therapist to help you work through this sort of question?