My office called me and then I asked the specific level (they had just said it looked great and high). If they haven't called in a few days I would call them. Then if you are nervous you can ask for another one, but I have heard after 6-7 weeks they aren't as accurate (as far as doubling goes..)
Mine called with the exact levels within 24 hrs and it was on the low side of normal I guess, so they started me on progesterone supp. that day. That was at 4 weeks and then they tested again at 9 weeks and called me again to tell me the levels and then at 11 weeks I got to stop taking the supp. My RE told me that the placenta takes over the progesterone at 10 weeks.
Re: Progesterone Level
DD#1 born June '09
DD#2 born April '11
TTC #3 as of July '14
My Dr has drawn blood every appt so far and he has always called me te next day with my levels which have all been excellent so far.