Conceiving

My boyfriend and I have been trying to conceive for about 6 months. I am beginning to wonder why it's not working though. He actually has a six year old from a previous marriage, so I know he's fine. I have been on birth control for 15 years and actually have become pregnant 3 times, which I did not go through with because of circumstances. My pregnancies were all because if me missing a few pills, never actually being off completely. The last 6 months are the first time in my adult life. I can't help but feel like I'm being punished. :( any input??