Why Am I Bleeding During 8 Weeks Of Pregnancy?

Hi. I'm 8th week pregnant today. I've been seeing doctor last monday because of the bleeding. Its not spotting like I used to have on 4th week. The doctor had a ultrasound on me and said the baby is ok. She can see the heartbeat. She gave me 3 days m.c, and if its happen to bleed again, she ask me to come and see her. So thats what i did today, went to see her. Did the ultrasound again, and everything is ok. But then she gave me 2 days m.c. If this happen again during those day, i might need to go to hospital. What can the doctor (hospital) help me? Some says, I may need to stay in the hospital until stable. I;m a bit worry and confuse. The last time i went to hospital, the doctor make me waited for him like half an hour and looks stupid to me. no explanation! I have job. Every time i went to work, i will take off day because of the bleeding and rush back to see doctor.