Pregnant 4 weeks and 5 days but HCG is only 52.6

Hi everyone, I finally after two years got my BFP on 6/9. I am off and on irregular with my menstrual cycle. I went 6 months straight getting my period on the 22nd of the month. I got my period 4/22 and then got another one on 5/11.

Went to the doctor and got all the blood work done on 6/12. My progesterone came back at 13.2 and my HCG came back 52.6. They want me to come back on 6/14 to take more blood to see if it doubles.

I am extremely nervous as I have been having major leg cramps(wakes me up at night) and tiny bit of spotting.

Has anyone else had an HCG so low and still had a healthy pregnancy?