Miscarriage ?

I’m 7 weeks. I started light bleeding on Saturday for about 30 mins and then it stopped. Then Monday the light bleeding started again this morning. Should I be worried? I’m not having any cramping or anything. I went to the Er earlier in the week and got a pelvic ultrasound and they said everything was fine with the baby but now this is starting to happen. The doctors said that bleeding will happen but how much blood is to much. I’m worried this is my first pregnancy.