Low rising HCG levels and positive outcomes??

Hello all I am pregnant with my first and my doctor has been watching my HCG levels. When I found out I was pregnant on 1/10/20 it was at 53 and they said I was 4 weeks and 6 days along based off the first day of my last period (December 8th 2019). On 1/19/20 I had another check and it was at 2205 and I had a vaginal ultrasound where they could see a gestational sac measuring 3.9mm but couldn’t see a yolk sac or fetal pole. At the time the i should have been about 6 weeks based off my last period but they told me it looked like I was closer to 5 weeks. So on 1/22/20 I came back in for another blood test and my HCG levels were at 4436 and because they had not doubled the doctor wanted to do another vaginal ultrasound. They again found the gestational sac and it measured at 6.4mm but still could not see a yolk sac or fetal pile. They told me it was concerning and didn’t look good since I should be about 6 weeks and 3 days and by this point they should see more than they are seeing. They told me to come back in in 48 hours for another blood draw and that we would go from there. So today 1/24/20 I had another HCG check and this time my levels were at about 4800 which means they only rose about 400 in the last 48 hours. Again the doctors said they are worried and that if they don’t rise enough by Monday that they will recommend a D&C treatment. I have only had mild cramping and no bleeding and I feel like my doctors are over reacting and jumping to conclusion since I am so early along and that they need to give it time. But again this is my first pregnancy and I’m scared to death it’s going to end up in miscarriage. Has anyone ever been through this and ended up having a normal heathy pregnancy??