Threatened miscarriage, still testing positive

Hello! So I found out I was pregnant last week. Monday I had what I thought was a full miscarriage. I went to the ER and they labeled it as a threatened miscarriage, I still had the pregnancy hormone in my blood, but it was very low. It was at 2.7. It’s Friday and I’ve taken 2 pregnancy tests, Wednesday and now today both not in the morning. And they both have read faint positive and I feel normal.

The ultrasound tech did not find anything resembling a pregnancy or ectopic on Monday. I’m confused and worried. I won’t be able to see my OB until next week at the earliest.

Has this happened to anyone else?

Update:

I took this test as my second test in the middle of the day a week ago. Because I started having cramps.