Does nut have to get inside you

Does nut have to get inside you to get pregnant. Me and my dude was fuckin and he took off the condom for the first and I kept telling him to put it back on but her insisted it felt better well as it was getting closer to climax I was watching him and he pulled out and started jackin off then nutted. Well I’m scared because he pre cums A LOT I’m just nervous he might be slow should I get an Plan B?