I have already had my period this month but I just had sex with my boyfriend and when I got home I noticed I was bleeding it was very light but bright red to pinkish what is this from

Bright red and pink mean its from irritation in your vaginal wall. If he was fingering you and had long nails, then that could do it, or if you were too dry when he entered you, that would break blood vessels as well. Just tell him to go easy, and you make sure you go easy too. It isn't good if this happens often, it can open you up to infections you don't want or need.

Tick

Rougher than usual sex will do it as well.