possible side effects of prometrium therapy during pregnancy

im 19 years old and 3 and one half months pregnant. my doctors placed me on oral prometrium for 2 months and just took me off of it. i have just recently learned there are possible negative side effects for my baby after birth. the doses were 200mg once a day for 3wks and 200mg twice a day for 4 weeks. they told me there were no possible side effects and that i was taking the drug to prevent miscarrage, then later they told me it was to get rid of what i recently found out was a fluid sack that is common in the 1st trimester of pregnancy. also, they waited until after i had been on the medication for 3 weeks to tell me i had certain restrictions, such as: no intercourse, dont stand or sit for over 2 hours and not to lift over 5lbs. i was also recently informed that not all doctors perscribe this treatment as it is a normal occurance in the first trimester and would like to know what side effects other than infertility that this drug could have on my baby and if it is at all increased by the fact that i was so early in pregnancy when it was taken.