progesterone

Terri
Hey guys, 
When I went to get my blood tested to see if I was pregnant bc of a miscarriage on Mother's Day my blood levels were going up just fine from 126.4 to 364 in 48 hrs but my progesterone levels were 13.4 and my doctor said he wanted them no lower than 16 and put me on progesterone orally 200mg twice a day. Should I be that concerned about it? At one point it's not that far off but low enough for him to have concerns. I don't see him till the six but I'm just worrying. Any advice? Thank you guys in advance!