3 weeks after D and C

So I have a follow up in about 12 days but when the nurse called, I asked if they will do blood work to see if my levels will be at 0 she said that early at 6 weeks 4 days it drops so rapidly that it won't be necessary, and I said ok! I took a test on Thursday which was 3 weeks and it was still positive, I hope AF shows soon, I heard and read D and C day is the day 1 of your first period so could this be a new pregnancy we BD 8 days later and and 2 other times, and advice what if I am??? Will I loose this baby too, if in I am, because it's to soon, or is it left over and taking time to go down?? I feel great and not sick like I did with the pregnancy I lost, my back hurts, lower, like my period is coming, I feel like I did with my daughter!! Advice? Input?