Help please :(

I'm having super light bleeding basically almost nothing. At first it was dark brown discharge and then it turned into a reddish orange but its basically nothing unless I stick a Qtip in there and there's blood on it. I also have to mention that I'm on Depo the shot. I'm actually worried. What could this mean? Is this like implantation bleeding? I am sexually active with my BF we use protection most of the time and other times we don't but he doesn't finish in me. Again I am on birth control.