I bled for my entire second pregnancy. I only made it to 30 weeks but do now have a healthy 5 year old boy. However, I had many other issues that contributed to the early delivery. I was on bedrest for the first 13 weeks and then again the last 2 before going into preterm labor.
Did the ultrasound show show any indication of why you were bleeding? I had a subchorreonic (sp) hemmorage - basically a bled between the placenta and uterine wall.
I would really try to take it easy and go to the ER if the bleeding ever increases.