I'm sorry you're having problems with your pregnancy
. About 30% of women experience some degree of bleeding during the early weeks of pregnancy, and about half of these women go on to have miscarriages despite taking medications designed to sustain their pregnancies. In other words, some fetuses cannot survive, no matter what doctors do. Unfortunately, women who have already had several miscarriages or premature births are more likely to do the same during subsequent pregnancies. Again, there isn't always an effective way to deal with this problem.
Your doctor is undoubtedly doing everything possible to help you through your pregnancy. Following her instructions will offer you the best chance for delivering a healthy baby.
I hope things go well for you.