Trying to conceive

Can I get some help? I’m really not understanding all of the way the DPO stuff works. My app shows my fertile window was from November 6-12 and that I ovulated the 10th. I had been testing hoping for a postiche result but each one I’ve taken has been negative. I keep thinking I’m seeing a faint positive in the ones I’m taking now but I feel like surely the line should have gotten darker. Right?!😫 I don’t know. But my period is 2 days late now and is about to skip this month looks like. I don’t know what to do☹️ I’m trying to be patient and keeping calm and not think about it so much but it’s super hard. I’ve been seeing brown discharge for the past 24 hours. It started out much more, now it’s sort of going away. I usually brown before my periods so I don’t know what to expect at this point. I have no other symptoms other than maybe slight dizziness and constant urinating. The urinating I always get before my period as well😤. My boobs sort of feel funny too but they don’t hurt to the touch.