Uproteed sex with my bf

Patient: I had sex with my bf and I was fertile that time. We dont have any artificial method but rather do the natural way which is withdrawal. Im worried because i might get pregnant so I decided to take pt test twice and It was all negative. I also had my period last day of the month btw. But this may and june, I didnt have my period yet and that keeps me more t worried. Just wanna ask if theres a possibility to me to get pregnant bcos of late mens? Even I had my period after We had sex? There’s still a possibility? I dont feel any morning sickness.

Symptoms: Absence of menstruation