get thee to a nunnery

Pat is not feeling very well and he decides to go to a doctor.

While he is waiting in the doctor's reception room, a nun comes out of the doctor's office. She looks very ashen, drawn and haggard.

Pat goes into the doctor's office and says to the doctor: "I just saw a nun leaving who looked absolutely terrible. I have never seen a woman look worse."

The doctor says: "I just told her that she is pregnant."

Pat exclaims: "Oh my, is she?"

The doctor responds: "No, but it sure cured her hiccups."