Help with HCG level...

Ok my results came back as 66.32 IU/ml and im just confused as if that means just 66 or.. Does the decimal mean anything. The reason im asking is im 15 weeks and I seen baby measuring perfect on ultrasound Monday moving around ect. It just scared me because all the HCG charts ive seen say my level should be between 9000-69000 (I just rounded)

Does that mean my level is just 66? Should I be worried? My drs office is closed on the weekends and I just seen my results in the health portal. My HCG level was tested on Monday right after I had my ultrasound.

Thanks in advance ladies!!!