Everything Has Changed Now

Penelope Bridgerton is left alone in her marital home, feeling lonely and lost when she has an unexpected revelation. She discovers that she is with child, two days after she sent the queen and her mother in law letters of being Lady Whistledown. She couldn't tell Colin, not after he still remained distanced from her, even after she poured her heart out to him and begged him to love her. Penelope decided she would flee Mayfair for the sake and the happiness of her child.
Will Colin be able to stop her from going when he finds out she is missing?

This story starts in season 3 episode 8 after Francesca's wedding, before the Butterfly Ball. As per the conversation between Polin at the Butterfly ball, it seems Colin was not staying with Pen in their house and she was all alone or they were apart even while being in the same house, it was not clear. I felt as though he had to be with her at such a time as a support and this is when Pen starts realising how lonely she is in this marriage. Here he is not staying with her.