I was in the moment and think I screwed up

I just started dating this guy. He's so nice. he's everything I've ever wanted. He's my rough around the edges country boy with a big heart and a great sense of humour. I'm just loving him and wondering where he's been all my life. Anyways today we were in his shop doing an engine swap and it was getting a little late and I was like I gotta head home type thing (we'd be there working for maybe 6-7) hours) and he was like ok I'm gonna walk you out. I was like ok. Got to my car and he pushed me against the door and kissed me and it was a hot and heavy moment and we jumped into my car and had sex. He asked me where he should cum because he knows my car is my baby and I wouldn't want a mess all over. and in the moment I said in me. He asked if I was sure and I said yes and he did. It felt amazing. I've never had that before. But I got my little glow pop up tonight saying don't forget to log because it's an important week for me because I'm right at the highest point of ovulation. I was like oh no. I wasn't even thinking. I wasn't even planning on having sex. It just happened unexpectedly. I wasn't even wearing sexy underwear. like I was rocking a bikini bottom which I only ever wear when I'm not having sex. it's always something cheeky. Ahhh. I'm just praying that we'll be in the clear. and now I'm seriously looking into birth control because I'm not just recently in this serious relationship.