can I be pregnant??

Amaya
I'm on the birth control method of patches and last Monday was my change day (the last patch of month before my off week). But it was also the day before I was supposed to start my period. I've never had unprotected sex. We always use condoms and I'm on birth control. The last time we had sex was at the beginning of the month (September). Now that it's my off week when I normally have my period it has yet to come. It's been over a week now and every now and then I get the feeling that I'm about to start but then nothing happens. Is there a chance of pregnancy or maybe my patches threw it off??