Effectiveness

I need some advice. I've been on the pill for a quite a while, but I've never been in a committed relationship so the majority of my sexual encounters have involved a condem/pulling out. For the first time, I'm in an honest and committed relationship, so we aren't using a condom and he's finished in me on numerous occasions. I'm suppose to be getting my period any day now and I'm kind of freaking out a little. How effective is the pill? I've looked online and done some research, but it would be great hearing some personal experience stories as well. 

Thanks ladies, I really appreciate it!