At the point of conception, I was a mistake...a lack of judgement, a moment of passion that turned into a lifetime of regret that a young woman surely wished would just go away.  

First of all, the world is definitely a better place with you in it. It is none of my business, but your birth mother did carry you to term (I am assuming, and well, you know what that does). So it seems that she didn't want you to not happen, for whatever reason. I shall also presume to say that it seems you have some good parents. I am blathering like this because it made me very sad to read the above. But you have aptly demonstrated there is no one answer.