Teece...I think it depends on your body. I've gotten it while on progesterone and always on time. I also stopped taking the progesterone a couple of day prior to

when I tested

before but I won't suggest doing that. I did that my last cycle and even though I tested

at 10dpiui, I got pg and went about a day without the progesterone.
I definately wait until you are "officially" late until you stop it.
I know it's hard to keep taking it after a

. It's frustrating and you just want to scream.
Hang in there...if it does turn out to be a real

, I'm really

you on for the IVF cycle!