Help PLEASE!

I’ve had sex around my fertile window according to the app. Unprotected and he came each time. My period ended up being late and it came. It lasted for a week. It’s now 13 days since and 3 days ago I had ALOT of brown discharge now I’m bleeding. What does this mean?? I took a test when I was a week late. It was negative. According to the app I’m also around my ovulation week.