Hello, and I hope I can help you today. Anxiety is not normally a side effect of birth control, but if you are taking a triphasic (pill that has a different hormone dose every week) pill your hormones are at the highest level in the third week of the pack, which may give you PMS symptoms. So you may be having some type of reaction to the hormone fluctuations.. I suggest you speak with your healthcare provider and try switching to a lower dose pill and also one that is the same hormone dose all month, called monophasic. There is a monophasic version of the pill you are on, called Previfem (without the tri) but I think personally you would benefit from a completely different kind of hormone if you have mood side effects. I hope I was able to answer your question today and that my advice was helpful. Best wishes, Dr. Brown