Hi Everyone - I'm onto my fourth pregnancy in 12 months and was wondering if anyone knows the rule on the HCG doubling time debate. I was feeling so positive after my first beta came back strong, only to be told by the clinic nurse yesterday that, in her exact words "wasn't looking good" because my numbers hadn't doubled in the 48 hours. They were 204 on Thursday at 14dpo and 331 yesterday at 16dpo - everything I read on the net says anything from 48-72 hours is normal and have worked out my numbers would have definitely doubled by the 72 hours and have gone up 62% in the 48 hours. Now I'm sitting here stressing until I have to re-test on Monday but just thought I'd ask if anyone had any experience with this themselves. I don't know who/what to believe!