i wanted to know why i haven't gotten my period. i've been on the pill for years, but at the beginning of this cycle, i was out of town and forgot my RX. i started it when i came back. when my placebo pill week came, i had sex a day before my period would normally have started. we didn't use protection, but i took plan b 48 hours later. i am about to start a new cycle of regular birth control pills, but my period hasn't come. could i be pregnant? what else could it be?