Bleeding after sex

Had three episodes with bleeding, mild bleeding after sex about a week or so ago and had an abdominal ultrasound where they confirmed everything was great and the baby was measuring 7wks 4 days, so today I'm about 8 weeks and three days and we had a pretty intense sex session this afternoon.....damn hormones are making me crazy want it......then I was on my way to work and I bleed a lot.....I know there's not a lot they can do, but I'm still so worried .....:(