Miscarriage?

I'm not sure if it's my period of having a miscarriage.. So I've been having very bad cramps & I had back pain the other day. Well I just went to the bathroom and when I wiped I had about two or three dark "coffee" brown color clots or at least that's what I thought they were.. They weren't very small I'd say they were a medium size.. Could this have been a miscarriage ?