what's wrong with me?!

Na
So since I had my son in January of 2016 I started the depo shortly after that. Three months later I never went back to get my next shot. I didn't get my period or anything until January of 2017! But now that I'm back on my regular cycle there is something wrong. My normal period Always starts on the 10th and ends on the 16th. For two days I'm clear of my period then during random times I'll cramp and start bleeding again for about 5-8 hours, it will stop then the same thing. I don't really know what to do? And I definitely know this isn't normal!