What Causes Intermittent And Frequent Periods While On Depo Shot?

ok, This is my 2nd time on the depo shot. I had tried the patch and when back on the depo shot because I didn't like the patch.. But the problem this time is I get my period one day and then like two days later it will go away, but then like a few days later I will get my period again.. this has been going on for months.. Im just sick of having period so much.. what should I do? I still wanna be on some type of birth control tho.