Thanks everyone for your replies.
Briggsy's Girl- I will be taking those tips tomorrow. Was the transfer with you BFP difficult as well?

Juniper- I'm sorry you had an awful experience. I don't think the doc will come out and say it is a contribution, but if your uterus is contracting at the time of transfer, it can't be good.

littlemissmoo- You poor thing. I feel the pain. I also had a retroverted uterus and my bladder was full too. I asked about ultrasound, but the FS said it doesn't give them a clear picture of the cervix.

BW- I hope I don't have that, but thanks for the info. FX things will go smoothly with my practise tomorrow.

I will let you know how I get on tomorrow.