Lately ive been having these weird shooting sideways pains underneath my belly button going across from near my hip bone to the other hip bone, like where you would have your period cramps. Except these arnt cramps like i thought they were at first but then they started to get sharper and more able to locate. Ive had my period for about 3 weeks now and ive been on the pill for 4 months. The first time i had my period on the pill was when i was supposed to get it and only lasted 4 days. Now i got it for 3 weeks and almost a month early? What could this be?