Ok I Period On Been On Time Every Month Give

Ok I period on been on time every month give or take 1 or 2 days. Last month was three days late and only had two days of spoting. My periods are a big flow I use super plus tampons go through 5-9 a day plus a pad and last 7 days. I had been nausea all last month and this month also with extreme migraine headaches. My period was 10 days late. Woke up in so much pain from a deep sleep on my side near my ovary. Cover the toilet and blood was really bad. Only had bleeding for that day and a half everything else I've been spotting. I am still having pain in my side and it now period pain. I am sexually active. What do you think is the problem. And I am still nauseated