What Causes Vaginal Bleeding During Pregnancy?

am pregnant with 9 weeks, but the problem that i have is that am bleeding,was attending the hospital and under go several ultra sound test and the doctoe said that the baby is fine and there is no any problem in the uterus,and he advice to take premolute depot once a week for five weeks,have alredy take 3,but for the last 4 days now i found that the bleeding is comes out with a bad smell,i went to the hospital again we do ultra sound and the doct said he didint find anything bad,the baby is verry active my i sould wash the vigina every time,am trying to do that but am still smell it,is going to be a problem please advice doctor