My Hcg Levels Were In The 17,000 Last Monday. I

My hcg levels were in the 17,000 last Monday. I had an ultrasound then as well. The sac measured 6wks & 6 days. I went back today for another ultrasound. It measured 6wks & 2days. The sac was empty at both appointments. I have had no pains or bleeding. I'm not sure what I should do. The doctor suggested that I have a DNC. Should I wait, get a second opinion, or go through with the DNC?