M.M.
Unfortunately, I had 3 miscarriages a few years ago. Each of them started with spotting and cramping. Eventually they were pretty heavy periods. However, I had a pregnancy test prior to this happening and it was positive.
The best way to find out what happened is to see your doctor. He/she may be able to tell if you had a miscarriage. Either way, you should have a check up since ovarian cancer runs in your family. I don't think this has anything to do with that but at least you can find out if you have any cysts. Sometimes stress can cause your period to do some strange things.
If you did have a miscarriage, you probably do not need to do anything else.
Good Luck!