How long would sperm have lasted in his urethra after ejaculation?

We don't like using condoms and i dont like any other birth control methods in my body. My body is very sensative, but i think condoms would be the best thing for us to use. It will also releive me from stress of worrying.

My bf and i had sex and he pulled out. He then wiped sperm off with a towel. 45 minutes later i performed oral sex on him and then he penetrated me afterwards. Do you think there was sperm on his penis from before and i will become pregnant?