That can happen sometimes with periods. It's happened to me in the past. It could be due to stress, sudden weight gain, loss, etc. Are you sure you aren't pregnant. It could signal a miscarriage or spotting due to pregnancy. I have P.C.O.S., a condition where I get large cysts on my ovaries and they can rupture also causing bleeding and pain. I'd suggest you see a gynecologist to rule out any other medical condition.
