I am 14, and I've been taking tricyclen for almost two months now. last month i had my period on the 3rd day of the green pill, (reminder pill) which my mom said was the day i'm suppose to start, but now this month, it is the 3rd day and no period. i took antibiotics for my bladder infection this month, but i looked it up on the internet, and it said that not all of the antibiotics affect birth control, and if they do, it's only a little. is it possible that my period is late? or am i pregnant? i am paranoid of being pregnant, i really hope i am not.