I am 10 days late on my period. And I have brown stuff coming out of my vagina for the last 3 days. I have a 2 year old and never had any problems like this. What could be going on?

That's old blood. Usually it appears just before your period does.

I would bet that brown stuff is just blood. Sounds like something in you changed. Could just be a one time thing.

Old blood getting released is probably the culprit. That happens to me when I am late