Rainbow pregnancy - very nervous! Please read!

I just found out I'm pregnant! I'm only 3 weeks 4 days. However, I've been having progesterone checks for the past several months, and all have been low. I went in for my progesterone check this month 8 days after I ovulated, and they said my progesterone levels were good (didn't give me a number). Today is 5 days since the progesterone check, when I got my positive hpt, and my midwife doesn't think that the progesterone needs to be checked again because the check last week was good. Has anyone ever had low progesterone before getting pregnant, then normal levels during pregnancy naturally? Should I push for another check? I am having some cramping that feels like period cramps and I'm nervous to have another MC.