Help please.

I started my periods on Sunday the 7th and they were 2 days late and I'm still on them day 9 and a few days ago it was like my periods were finishing up and I've woke up this morning with more blood and a sore stomache which feels like period cramp am so confused on why they ain't finishing because they normal finish within a week and now am on day 9 and my belly is sore why ain't they stopping! ??