Is It Safe To Use Duphaston During Pregnancy?

Hi, I am 8 wks pregnant now with my second child. during the 5-6 wk of my pregnancy i noticed some brownish discharge and I consulted my doctor. She advised me to use some tablet for vaginal use (do not remenber the name). I was not comfortable using those tablets coz it gave me severe burning sensation but the doctor refused to change the medicine or to allow me to have the tablet orally(it was for oral uses as well). I consulted another doctor (who did my first delivery) for second opinion and he advised me to take Duphaston tablets for a month. But I read on the internet that the use of this medicine can cause fetal death (especially in 1st trimestor). please advise?