Depo shots!

So I had my last depo shot about three years ago. I only got two shots then stopped due to it made me have a period for 4 months straight! I couldn't handle it. It messed me up bad!! We have been TTC for over a year but I was wondering if my past with depo could have anything to do with it. The Dr said it shouldn't have bothered anything fertility wise but over a year of trying and only 22 yrs old I'm starting to think differently. Anyone have any depo insight or experiences? Did you conceive after depo? Or have trouble after depo?