SOS! What does this look like

*TMI* so I’m about 8-10 days late on AF. (Estimated) I have medium/heavy flow periods but only ever late for a day or two. I’ve had Faint positive tests, some negative. Not sure entirely when I ovulated, I also have endometriosis. I’ve had all the pregnancy symptoms, (nausea,vertigo,backache,severe food aversion,lack of energy) I’m a very active personal trainer and can’t even get myself to the gym! I noticed this today, it’s not enough blood for a pad or tampon, and only shows when I use the restroom. What can this be? I have NEVER had a period like this. I usually have SEVERE pain (endometriosis) and ALOT more bleeding. I’m 23 and my period has looked the same and felt the same since I was 13.