first of all congratulations on your pregnancy.
i can understand your concern, but why do you want to use it?
has your obstetrician suggested you to use it?
also, do you have any deficiency of progesterone? see, i believe
to use a certain medicine there must be a reason for it. but if there is no reason, its pointless don't you think?
you should rather be taking iron folic acid tablets and good healthy diet don't you think?
though there is no side effect as such but still. i would suggest you consult with your obstetrician in person and discuss this with her. take medicines only if they are required.
Dr. Anil Kumar Jain