What is this brown stain on my underwear?!?

Hello everyone, so today when I went to the restroom I noticed my underwear had a big brown stain on it, ( I do wipe correctly btw) it didn’t have any smell to it and usually my period blood smells. it was also straight up dry so if it was period blood I suppose it would have been watery.

According to Glow, I started ovulating 2 days ago and i haven’t participated in any kind of sexual activity since my last period. What could this be?

thank you in advance 🤍

I would also like to add that my menstrual cycle is irregular but for the past two months it hasn’t been and this app has predicted my last two periods spot on. Could this be that my period is starting early, ( according to Glow I started ovulating 2 days ago😕)