anyone else?

So this has never happened before but about 3 weeks ago I had unprotected sex with my SO 2 different times both he came in me (i am on the pill have been for 4 months) so this period has just been very off the first 2 days it was really really heavy i mean changing pads every hour. Now its very light. However I have been very nauseous have had stomachaches and constant migraines also very tired all the time. This has never happened to me ever since I've had my period ive never been nauseous or gotten headaches. Does this sound normal?