The pill as your only form of protection

I have been on the pill for somewhere around 8 years now and have only really used it to help with my period and the cramps that accompany it. I have recently started dating someone and want to have sex with him and allow him to cum in me. I have just been afraid to do so because I have apprehensions of the effectiveness of the pill. Yes I know that it say it’s 91% effective and all but I still get nervous. I take my pill everyday and almost NEVER miss a pill because of the pain that I will have to deal with if I do. Just kind of looking for reassurance that it really is that effective. And I know that it’s not 100% effective so there will always be a chance and I’m ok with that be that it is a small chance.