I am fairly regular on my periods, but this time I was late..by 3 days. Me and my boyfriend were fooling around with no clothes. We didnt have intercourse, nor have I ever had sex. But just to be sure, I took a pill. And m still not on my periods. I was suppose to have it on 25 Aug..I took the pill on 28 Aug and m still not on my periods. Do I have to worry?