Me&fiance have a child together and have been trying to conceive for 2 year's 9 month's. no luck... what do you think? secondary infertility?

Yes. Get checked out: Over 2 years is too long trying, either for a 1st child or in your case one more, especially at 21. This is a good time to see your obstetrician or a fertility specialist to help you to get pregnant again. We check you for ovulation issues like pcos, other hormonal problems, low egg supply, blocked tubes (did you have a c section?), problems inside your uterus or sperm problems for your fiance.