I have ocd and i also have anxiety, do any medications for ocd or anxiety affect the birth control pill?

Some may/ most no: The question is rather broad because there are so many different medications used to treat obsessive-compulsive disorder and i see that you live in australia. You probably have other medications that we do not have available in the United States. I would simply recommend you talk to your psychiatrist prescribing physician about which ones interact with your birth control medication. Your doctor can easily find information regarding that.