9 Weeks 3 Days

My pregnancy 9 weeks 3 days now but recently went for 1st scanning and doc said my baby size is 6 weeks. Most probably because my irregular menses/period. So the date will be slightly inaccurate. But yesterday I had bleeding and so were today. Went to doc, and scan again, the baby sack is still there but she said if in 3 days still bleeding, I should go to hospital. I'm worried. Is this a sign of miscarriage? Pls help..