Me & my ex-boyfriend have being trying for 6yrs now and I can't get pregnant. Then all of a sudden we broke up because of the issue. He wanted a child bad. Then like a year later he had sex with two girls which both became pregnant. He's not sure if he's the father yet, because we both are the same age and none of us have kids, or disease. So I'm so confuse on how (if he is the father) did he get the other girls pregnant and not me. I went the doctor and they said I can have as many kids as I want. Was there something I'm missing or was it not meant for me and him. And if that is the case, I've been wanting children since 16 and I'm 24 now and still no child.:(

Have you had all of the testing that is involved in a fertility workup? It can be quite extensive. Ask your gyn for a full workup or a referral to a reproductive endocrinologist. This would be the only way to know for sure whether you have any fertility issues. Sometimes too it can actually be how your body responds to his sperm, so he would need to be part of the testing as well.
I hope he will take measures (dna testing) to find out for sure whether he is the father or not of the other children.
As difficult as it may be, sometimes couples will break up due to fertility issues.