Well, If you're on a medicated cycle it's more likely that they know what they are doing. I know of a fet that the transfer date was scheduled 6 weeks ahead of time, and succeeded - meaning they direct you with the meds to be hormonally ready for the transfer -not necessarily ovulating, but the lining etc . Regardless - I absolutely think you should call them, and call again if you didn't get a straight answer. You go thru A LOT and you need to know and make sure everything is done best. Even if you think that makes you a nag, it's such a small price to pay.
I saw a GP yesterday when the pain persevered. It was quite a scene really, leaving my ILs house trying not to be a drama queen
