We went for our second beta on Friday and our hcg went from 164 to 536. Progesterone from 64 to 72. So the pregnancy is sticking and sticking well! Also, the docs are taking bets that it's twins. My mother (a neonatal intensive care nurse) is worried it might be triplets. I think our RE is also worried, cause they scheduled an ultrasound for Thursday, which will be five weeks. Yikes!