how low is too low?

i got my blood drawn when i was 7 weeks along and they took my progesterone levels because they believe that’s what caused my MC in june. i am 8 weeks and 1 day but when they drew my blood my progesterone levels were 20.1. i looked up the range for progesterone in early pregnancy and it seems i’m in the middle... i don’t want to take it if i don’t need to and i really don’t think it’s what caused my miscarriage. i was under a lot of stress and drinking heavily before i found out i was pregnant that time, as well as taking my leftover zofran from my sons pregnancy because of my HG (severe morning sickness).

(when scheduling my appointment for this pregnancy i mentioned morning sickness again and asked for more zofran and they said they don’t prescribe it before 10 weeks which is well before when i was taking it with the MC so that’s why i don’t think it was low progesterone. and i didn’t have the miscarriage before i knew, i went to the ultrasound for the first appointment and there was no heartbeat so i think it was more to do with physical and environmental factors than my progesterone level)

because of it being the weekend and then labor day i still haven’t been able to pick up the progesterone and i am not being seen again by my OB until the end of the month, which is when they said i would stop taking it... it’s kind of expensive so i’m wondering if 20.1 is really that low of a level for progesterone, would anyone with levels around there recommend that i take it? thank you!