since i was 13 i was on birth control and at 15 put on depo. I had irregular periods and cysts on my ovaries. I was wondering, because i'm 17 now and i had sex yesterday. We used a condom, but i know condoms aren't 100% effective..is there still a possibility i could get pregnant? Even though i only get 2 periods roughly a year? My last period was a month ago..i'm really just curious..my last shot of depo was october of 2005, so it's been a while and i only get 2 periods a year..is that bad? I've seen doctors about it, but all they say is my body has to get back on track, but i don't know it seems like it's been long enough?