Hi...i am 21 weeks pregnant and my dr has been giving me susten 400mg from 4 months as far as i read about this medicine it for females having past history of miscarriage and low progesterone but this is my first pregnancy and not sure about low progesterone also some websites say it is not safe to take it for long as it can cause birth deffects to the baby. I am terribly scared. Can someone please advise