First, thank you all for your kind words. I'm thinking of all of you in the 2ww, and waiting and hoping for you. It has been a crazy week, I have long experiments everyday and I'm packing to move this Friday, so I just have time for a quick update.
The RE's policy is that the blood beta is determined in a single draw at 17 DPO, which will be on Sunday. So I have to wait. The thing that is keeping me sane is the the urine HPTs are steadily and clearly getting stronger, clearly in a 24 hour period and without doubt in a 48 hour one. Shannon's point that these are too crude to be accurate definitely stands, but its reassuring to see the darkening nonetheless.