My Boyfriend Cut My Vagina With His Finger Nail This

My boyfriend cut my vagina with his finger nail this morning and I didn't realize it until I went to take a shower and saw a little bit of blood on my underwear. I saw there was a cut and so a splashed some water on it. And then not long after it became a small sore brown bump. I'm really scared I don't know what it is or how to treat it