FAM method questions!!! 🆘

Okay so I’ve been using this method for quite some time. I haven’t had sex a lot but so far everything’s been alright. My fertile window is spot on with this app. I have ewcm when it says I should and so on. I know I can’t trust this app 100% but it has helped greatly. So my question is if I know when my window is, can I have sex and be okay? Meaning after my fertile window is over?? My bf never cums in me and we’ve used the pullout method before but we only have sex when I know for sure I’m not ovulating. Usually a week before my period. So how can you get pregnant if you’re not ovulating? I know sperm can live for up to 5 days but if you plan it out shouldn’t you be okay???

**im getting on birth control next week but I was just curious**

** also just trying to learn as much as possible about the female body **

Please no mean comments!