Birth Control and Unprotected Sex?

So i just recently started having sex with my boyfriend. I was a virgin. I’m on the pill and have been for years because or PCOS. I let him cum in me because it feels so good for both of us, but what is the likely good that my BC would fail? I’m just overthinking it but wanted others opinions. And before anyone says anything about STD’s, i made him get tested before we had sex and he is clean!