Hi Katherine- First, congratulations! I am new to all this myself so I can't comment too much on the hcg (although my recollection is that it can be normal for the doubling time to slow somewhat after you reach 1000- hopefully folks with more experience will chime in) but as for the progesterone- I think that it's important to get that checked asap. It's true that you can't measure the full effect in the blood, but if your progesterone was say 9, I would definitely want to supplement further, vs. if it was say 30. It's your pregnancy and there's no harm in testing your progesterone (or even in adding PIO if need be) so I would push back on your RE. Just some advice from another newbie... Wishing you luck and congratulations again.