Reconstruct a question, answer pair from this explanation: The relevant sentence in the passage is: It is revealed that Georgina is pregnant with what she says is Dan's child.
Q:Context: The third season finale has Georgina return from Belarus wearing a blond wig and large coat, desperately seeking the help of various Upper-East Siders with her "problem." However, they all dismiss Georgina, as Blair is too worried about Chuck to listen to her, and Dan and Serena do not notice her new disguise while at the hospital. In the season finale, Georgina arrives at the loft with "something" of Dan's. It is revealed that Georgina is pregnant with what she says is Dan's child.

Question: when does georgina tell dan she is pregnant?
A:third season finale