when Luke walked in Lorelai's room he saw her looking at her stomach in the mirror and he asked why she was doing that. She told him I'm pregnant and I don't know who the father is as her voice cracked. Luke walked over to her and brought her to sit on her bed and he let her cry in his arms until she was done crying. He asked her who the other father might be and she said Christopher Hayden. He asked her how and she said that she dated him a little while before dating Luke. Luke said even if it's Christopher's baby that he'll treat her the same as if the baby was his. She asked him for a hair sample for the paternity test and he gave it to her and then they walked to school.