Hey sen -- I do think it would be a good idea to see a doctor sooner than later. 6 pads in 3 hours is indicating the kind of excessive bleeding more aligned with an internal injury. That's also quite a lot of bleeding for a period too, to put it into perspective. I'd advise the same thing in that scenario too. When you said you didn't want to go just yet in your initial post, what did you mean? Is it just that you wanted to hear our perspective, or is there another barrier?
It's very important to view what many consider "foreplay" as sex; sex is not just the act of putting a penis somewhere. Our page
What Is Foreplay? goes into that perspective, and I think it would be good for you to read over. I'm assuming from your post that you didn't do activities typically categorized as foreplay, which I think could have contributed to the bleeding and the pain. When people with vaginas become aroused, their vagina will naturally lubricate, which enhances the ease and pleasure of vaginal intercourse. Often people refer to this as "getting wet." Your vaginal opening will also loosen a little. Though your brain is feeling ready to have sex, sometimes your physical body needs some extra time or focus. Without enough lubrication, tears or other injuries can happen within the vagina during sex.
I also wanted to check in about your experience losing your virginity, this bleeding aside. How are you feeling? Do you have any questions about that?