Hi! First off, congrats! I just wanted to chime in and let you know that my BFP was 12DPO (and 12 days post conception) and my first beta, recorded two days later, was 67.
So, 24, at 10ish (?) days post transfer sounds like it could be a-ok to me.
Edit: it was actually 12DPO for the BFP, so 14DPO for the 67, I just double checked. Still, that means it would have been in the single digits at 10DPO! My temperature was also not going up, so I had to stop temping - I was driving myself nuts.
Re: I think I have a squinter!!! BFP???
BFP- 10-16-14 EDD 6/13/15: MC 12-1-14
"It is better to light a candle than curse the darkness." - Eleanor Roosevelt