Hello Im 22weeks Pregnant Now & My Dr. Prescribed Me

hello im 22weeks pregnant now & my dr. prescribed me utrogestan 200mg vaginal suppository only at bedtime for 2 weeks because of my early contractions & feeling of fullness during ambulation.. I've read about this medication that it is only use at early pregnancy like 1st trimester & it does not treat preterm labor.. is it safe for me & for my baby?i'm now on my 2nd trimester.. is this a right medication for my condition?