Non menstrual bleeding accompanied by sudden pains. now on cycle, passing unusual clots near the end of cycle. one was the size of a small fist today.

Large clots: may be variation, stress, fibroids or may have been a miscarriage or ectopic . So would follow up with doc urgent care may need sonogram to rule out retained products of pregnancy or ectopic

Need to be seen: Pain and bleeding can be symptoms of pelvic infections. You need to be seen for a full history, exam, and appropriate testing ASAP. Pain is your body's way of telling you something is wrong. It is best to listen. Hope this helps and you feel better fast.