Depo shot....LONG

Shelby
My last depo shot was either in April, May or June of 2012..I know it probably sounds silly that I can't remember, but I genuinely can't. I could probably figure it out if I called my old doctors office...anyway. My fiancé and I started dating in March of 2012 and have never used protection. It's been about 8 months now where we've actually been TRYING to conceive with no luck (we've always hoped it would happen though.) I am getting extremely frustrated and losing hope, just like anyone else who is TTC I'm sure. My doctor said she can't do much until it's been a full year TTC, and even then she said she still can't do much unless I get better health insurance...I'm worried. She has also said she doesn't think it'd have anything to do with me being on depo. Although she has a degree, I don't know if I agree with her. Sometimes I do think it's because of being on depo. I am also over weight and have been working on losing it and know that could be a bit of a factor..but I also know women who are heavier set than me who have gotten pregnant easily. Does anyone else on here think I may not be getting pregnant because of depo? What can I really do?