Hello, welcome to Scarleteen! I'm sorry to hear that you're bleeding after your first time, it must be a little scary. I'm not a doctor, and so I can't say for sure what the issue is, but it's common to bleed after sex when the delicate tissue of the vulva and vagina get damaged. This could be for a number of reasons: there might not have been enough lubrication, or maybe sex was too fast or too rough, or maybe you weren't relaxed and aroused. If it doesn't get better within a week after sex, I'd recommend visiting the doctor. Is there any pain or soreness still?