I think it sounds pretty normal but you also may have started your period coincidentally at the wrong time. Ask your doctor about iron tablets as my doctor does say not to take them unless they've checked that I need them. Anniebrooke is right though that if you are shown to have intermittent anemia, they may supplement you which can be really helpful. Again, I think this is pretty normal. I also had about a day's worth of bleeding after first time sex and then spotting after for a couple of days.
If it hasn't stopped bleeding by now, do go to the doctor (and take an iron tablet. You don't want to get anemic on top of everything else.)
I bled for almost a full day when I had sex for the first time, and it was a lot. I don't know why, but back then we thought it was normal. It stopped, and it never happened again.
If it doesn't stop, or happens again, see your doctor.
Was it rough sex? It might have caused some inflammation in your cervix area. A torn hymen isn’t really a real thing anymore because hymen’s can be torn with tampons, or if a woman is athletic or exercises a lot etc.. Maybe you should use lubrication next time. If it’s not your cycle being on, do go see a doctor.
Six hours ago? Yes, probably normal. I assume you are certain it isn't your menstrual period? If you are sure of that, you might try sitting on a cold compress (cold, wet towel or similar).