im not sure if youre the right doctor to ask but i started taking birth control pills and its been two weeks, i am halfway through the third week of pills, and i have a residual pain in my lower abdomen that has lasted over 36 hours.. should i be worried? before taking the pill i was getting my period every 2 weeks, so if i wasnt on the pill, my period would have started this monday.. its wednesday but i dont know whats going on.