MGC Bertie - sorry about your BFN. I always started resting about 14dpo when doing pregnyl and only ever had the residual of the pregnyl. When I had my success on transfer 7 I tested at 12 dpo and it was blindingly positive.
Have you been with Fertility First before. Anne was my FS before I flicked to Sacks after I lost the twins last Jan as she does not believe in NK Cells & will not treat them. I had to force her to let me try the Pred & Clexane which resulted in that pregnancy. I have swapped between her & Sacks a bit in 2013 but have to stay with Sacks now for PGD. Also if you haven't been with her before she will do all the testing all over again.
Her nurses & admin are fantastic & I really like the girls there.