Why am I bleeding?

Aliyah

I have sex in 4 of my 7 days ovulating and even 3 days before and a couple days after. I took a pregnancy test a couple days ago and it was negative. My period is in 5 days. I had sex with my SO today and I was bleeding. It’s stopped now but why am I bleeding? Is It implantation bleeding? Could there still be a chance to get a positive pregnancy test?