Random heavvvvy bleeding 6 days after late period ended!?

So here's some important details. I'm 20.....On Feb 16th I had a D&C (it was not for a miscarriage). At my follow up almost 2 weeks later, the dr told me he took a sample and it showed that my period should have came on Feb 22. I didn't end up getting it until Mar 11th. It lasted Mar 11-15. It was pretty normal. Today, I wake up saturated in blood! I go sit on the toilet and bleed like a faucet. It wasn't clotty, but bright red and hemorrhaging. For a few hours I was replacing a super tampon every 30-45 min! Then throughout the day it slowed down. It is now almost 1 AM and I'm bleeding lighter, but still bright red. I also have had a bad headache and cramps all day with weakness and dizziness. Also, I better add that my boyfriend and I have been having unprotected sex almost every day since a week after my D&C. Does anyone have any ideas or experience with this? Thanks!!