Bleeding during intercourse

Patient: I am 20. I just had intercourse with my bf. during the process I was bleeding. I thought it was normal as woman do bleed during their first few tries so we kept going. Then it became more bloody. By the time we stopped, I was dripping blood. By the time I got home, the blood had already stopped. It was diluted red. I know i must check with a gyne. I checked the net and most of them said it was cancer. What’s going on?