accidentally deleted— HCG levels

I went to the doctor on monday for blood work to confirm pregnancy and I would have been about 3 weeks and 6 days, they just called me today and said that my level was at 88 and they want me to come in tomorrow where i’ll be 4 weeks 3 days to make sure my numbers are doubling. Does that level seem okay? I’m so so nervous.

also i’ve taken more tests and my lines keep getting darker