Anxiety about Awaiting Period

Sarah
I suffer from extreme anxiety about the possibility of not getting my period. Every. Month. It has gone too far. I have been on the pill continuously for a few year, and I always use a condom when having sex. How can I help myself from thinking I am pregnant every time I am awaiting my period? Does anyone else ever feel like this? I just want to control my anxiety and try to help myself from having this fear.