Not sure

Maribeth
So I went last week to the doctor thinking I was around 6-7 weeks. The nurse practitioner couldn't find a gestational sac and was worried I would miscarry or ectopic. I did blood work that day and found out on Friday my levels were at 24,000. Then the blood work on Friday came back today and it's 22,000. So now they think I'm having a miscarriage. My progesterone levels were great and I have been feeling fine. I'm just not sure what is really going on. I had a miscarriage last year around 6 weeks, but I was bleeding early on and it just didn't feel like it was going to make it. This time around has been so different- no bleeding, sore BB's, slight cramps, and food cravings. 
Has anyone had their numbers go down but maintained a pregnancy? Or does it just keep dropping?