okay im on yaz birth control and im on the last 4 pills you know when im supposed to start my period! well i havent started it yet. and i had sex 4 times with in 4 weeks. and the first time i missed 2 pills and WITH OUT a condom it wasnt really even sex because he went half way in then back out and stopped. and he didnt ejaqulate or pre-ejaq. well the other 3 times were with a condom. so im on the last 4 pills and my period hasnt started yet. i took a test 2 days ago. it was NEGATIVE thank goodness. but im still a little worried because i havent started yet. and i took into consideration that i took the test before my missed period but only by a day or 2 and from what iv heard its more effective if i wait until after my missed period to take a test.