Did anybody have problems after the depo shot?

So I am trying to get pregnant that's why I stop getting the depo shot. I think I was supposed to go back in December or January but I got it in sept. Anyway I know it take 4-10 months for it to fully leave the body. But when I first got it I stopped and got pregnant . But now I'm trying it's not working. I been having pregnancy symptoms which is the affects from the depo shot. But I notice my nipples got a dark ring around it but not the whole thing. No they do not hurt. But I have been having sex a lot lately. I have been having cramps like my period finna come on but it don't. No I do not know when my period is coming . Last time I had one was in sept-October 2015 for like 3 weeks