Fertile window finished Friday... fertile mucus today, on CD 19?? Am I ovulating late??

Hi guys, so my partner and I just started “not trying not preventing” and I finished my fertile window last Friday or Thursday.. I DID NOT CHECK MY MUCUS AT THIS TIME, Im just using the apps calendar to keep me updated. I had white clumpy mucus Saturday, and had unprotected sex Saturday night and Sunday night... now it’s Monday and I checked my mucus out of curiosity and it was the biggest egg white mucus I’ve seen... like I’m really fertile! Can I be ovulating on CD 19??? What is happening!!