It’s just not there...TMI⁉️

So I know this isn’t a positive ovulation yet but my periods are irregular. Currently 15 dpo AF due yesterday and was a no show, so far nothing today but I’ve been having light brown discharge since last tuesday. It’s not always like this. Usually very very light but still there. Now I usually start my period from day one, meaning no brownish or spotting for a day than heavier, I just start bleeding from day 1. So I don’t think this is AF at all. Took an ovulation test 3 days after AF out of curiosity which looked darker than this but I went based of the app instead which says I’m currently 15 dpo. So far negative results so I decided to take one of these to see what the hell is going on. Btw; i don’t have PCOS. I know it’s negative but does this mean I’m suppose to ovulate soon? I know it’s not pregnancy because I took an hpt and came out negative. Advice?