BLEEDING....HELP

I had sex with my boyfriend earlier today and it went well. I was into it but at times it has hard for him to put it in but we managed and our day went on. I got home about 4 hours ago and I went to the washroom and there was quite a bit of blood in my underwear. I have experienced spotting after sex before but it's NEVER been this much. my period ended almost a week ago. should I be worried? or is this normal?