Depo Shot Spotting

Haley • Taurus, Ravenclaw, poet. Sko Buffs!
So I'm on the second round of my depo shot and I'm not supposed to get my period, but they say spotting is okay for the first few months but it's month 4 or 5 now. They say it should go away after your first round... But I've been spotting pretty consistently this past week. Consistent but not heavy enough to constitute a period. I don't feel like I'm gaining weight and my breasts and back don't hurt, but I've been having stomach problems recently too. That could be for a number of reasons but the fact that they coincide worries me. Should I talk to my doctor? I've been thinking about calling a 24 hour nurse hotline and seeing what they have to say... Am Ioverreacting? Do you have any advice?