I understand your worry; I think there is a little of that with every step in this process!
I found this to be the hardest part of the process. I was constantly worried about mine, whether they would make it to day 3 or day 5. It's really stressful!! I'm glad your FS could reassure you. Fx for a 5 day transfer!
Ali - sending your little ones tons of growing vibes!
ali - I go back next Tuesday for another blood test and they will also do a scan that day! They wanted me to go in on Wednesday, but they were completely booked, so it looks like in 6 days I hopefully get to see something
I think I have one strong little one in there, but I will soon find out!
with this stuff. The other part of me wishes that none of us had to worry at all!
They might think I am crazy 
When I got my second beta, I went on the beta sites, calculating the exact hours between them based on the expected doubling times and the mean doubling rate. I'm something of a math dude, so that's just what I do with numbers, but then I realized I was being silly. As long as the numbers basically double every two days (and yours did), it means everything is going well! So that's a good number.
Woohooo!! Great number!!
to all you ladies and gent! I really do hope that there are plenty more successes in the next couple of weeks!! 