Talk to Gynecologist on Gyneacologist

Its my first pregnancy and 6th week. i was taking dup*ast*n 10 mg twice daily from start of pregnancy but then switched the doctor and she asked to stop taking it. I stopped it 3 days ago. Now i got to know that we shouldnt stop it from between and it prevents miscarriage. Now what should i do, can i start again after 3 days gap ? Cant go to that dr as i got the appointment for end of november. In that visit she asked me to go for ultrasound, it was 6.2 weeks 3 days ago, heartbeat was not there but she said it too early for heartbeat go again after 15 days it will be there Inshaa Allah. But CRL was 5.2mm which was good according to 6 weeks so she said dont take any other medicines only folic acid once a day.