KIND OF Unprotected sex....

I know that this is a stupid question, so I apologize in advance.

My bf and I had KIND OF unprotected sex today. We’ve always been vigilant about condoms because I can’t be on birth control. But tonight, we very briefly tried it without a condom. He DID NOT finish and I only let it happen for 15-20 seconds max.

I know the whole spiel about “it only takes one time” and “anytime you have unprotected sex...”. But please help me feel better here. Today is the last day of my fertile window, according to eve. Realistically, what are the chances I’m in the clear? I have ZERO interest in pregnancy. Please don’t try to just freak me out... I need some reassurance from you ladies. Thank you all 💕