Uterogestan is a natural progesterone and safer as compared to other synthetic progesterone. It may cause vaginal irritation
in few cases and rarely it can cause Hypospadias
in male infants specially when it is taken before 11weeks of pregnancy
. I t is FDA approved in certain high risk conditions to prevent pre-term deliveries from 16 weeks onwards.
In certain countries Doctors give this progesterone also during first few weeks of pregnancy in those women who has previous abortions due to progesterone deficiency
. even during IVF Doctors use progesterone to increase chances of implantation
and to maintain pregnancies. So it depends on your Doctor's choice also.
In your case, may be you can ask and understand the reason for her fear of weak pregnancy. According to your LMP, 5weeks pregnancy is fine.
I hope I have answered Your question. If any further query, you are most welcome.