My boyfriend and i had sex 3 days in one week. the first two days i was fertile (3&4 day of may? the third day i was ovulationing (5 day of May). he came in me all three times. my period started on the 20th of may it was normal very light though. two days after my period ended i started having very bad stomach cramps it feels like im going to have another period . my breast are a little sore and i have terrible head aches .. what might it it be ?