Heavy period and more

Last week I had extreme heavy bleeding, so much that I had to throw away my pants. I was 2 days late for my period and concerned it was a possible miscarriage. I contacted my OBGYN and she was also concerned and had me go in for tests. They came back negative. Heavy bleeding continued for one day and then was pretty much only spotting after that. I also experienced a really bad migraine (I’m guessing from the heavy bleeding) and diarrhea but now I’m really constipated. Has anyone had a similar issue? Any cause for concern that this could be more of a health issue? I have a follow up with my OBGYN but it’s not for a few weeks.