The patient claims to have requested a pregnancy test. This is a trans individual - do you not think that in the current climate the hospital wouldn't have been jumping backwards through flaming hoops to accommodate her demands?
I think she's mistaken. I have worked with surgeons in the past, and been present when they have clearly explained the implications of surgery and treatment to patients - any possible complications/ side effects etc, and the patients have confirmed that they have understood and are happy to go ahead.
I have then on occasion heard these same patients deny that X or Y was mentioned - and they certainly weren't told anything about Z! It's not lying, as such, it's just that it's human nature to want to go ahead and be "cured", and also to want to blame someone when that "cure" comes with even minor complications or restrictions (eg to diet etc as in gall bladder surgery) and to deny that they were told. They truly don't believe that they were informed.
I think that this TM has denied any chance that she could be pregnant and now - whether from guilt or another reason - cannot accept the responsibility.
I honestly do not think that any hospital would omit such a basic test procedure, particularly when is is easy, quick and cheap to administer, and carries no risk to the patient.