I found out last week I have hypothyroidism, I started levothyroxine sodium also last week. I'm on alesse birth control and was due to start my period yeasterday and didn't get it, it's always on time. The last time I had sex was in may and I used both a condom and the pill but I was late for the pill a few times that month, is it a higher possibility of pregnancy or just a late period from the new medication?