Weird bleeding???

I’m late for my period, af was due the 20th. I woke up this morning and went lee, when I wipes there was a TINY bit of blood in my mucus (which is creamy/slimy like with a white tint), I put a pad on thinking “yay my period is finally here”, butttt after that my cm turned a light brown color for about an hour, and now I have no blood/brown at all, I even *tmi* stuck my fingers up there to check and there wasn’t any blood at all, just a little brown mixed with my cm. I have absolutely no idea when I ovulated (if I even did), or when I supposed to get my period (cause I missed my “scheduled” af). Any insight on wtf this could be? Thank you all so much for any answers💞💞

Edit- I have taken tests, all negative, I haven’t in about a week, but I had an ultrasound a week ago and i was not pregnant. Could something have shown up by that long?? Should I test again?