Sore bruise like feeling in lower right abdomen. Ovary issue?

I've had this pain once or twice before but I have no idea what it is. It's in my lower right abdomen beside my pelvic bone. It feels like a bruise and I can only feel it when having , using a tampon or if I move a certain way. It started two days ago when I also got my period. My period lasted one day but it's only been two - three weeks since my last so maybe there was not much there to come out? My last period was because I stopped taking my birth control and lasted a bit. I think this period so soon to my last was because it would be my natural time for my cycle but I really have no idea. Just guessing. Anyway, the pain is just worry some. What could cause a pain like that?