Spotting/bleeding

I've had spotting and a little bleeding in the last week. Not enough to fill a liner but it is bright red. No cramping at all though. I went to the ER on 5/10/16 and ER Dr said there is no active bleed just irritated due to having sex. Ultrasound showed a strong heartbeat and fetus measuring the right size. Hcg levels were right range for what I was measuring. Still have some bleeding but lighter then when i went to ER. Have prenatal appointment on Monday 5/16/16. Am I wrong to be worried. I've never been pregnant before and it's only around the 8th week.