Low HCG @ 4weeks 3 days

I have 2 healthy kids 17 and 15 I am 41yrs and had a miscarriage in April at almost 6weeks. Found out today I am 4wks 3dys and my HCG is only at 30 not sure what to think? We have been TTC for 13yrs and went through <a href="https://glowing.com/glow-fertility-program">fertility treatment</a> off and on but stopped 3yrs ago and now concieved naturally 2 x.