Pain?

Ok! So I missed my period by 3 weeks and finally started, and I'm on day 5. Normally I have really painful periods but only for the first and second day! In my back and lower abdomen. Sometimes even my legs will hurt so bad. And it seems like blood clots coming out. Or chunks. However you want to say it. Ok to the point. So it's day 5 and I'm having the extreme day one day two cramps and back pain and clots of blood again.