No. The girl who is pregnant is the one who knocked on Dane's door when Grayson was visiting him. Grayson doesn't know her.
The other girl you are talking about appears at the beginning of the story and she's Grayson's "friend". She had a physical relationship with Grayson and I think also the ML of Kiss Me Liar. She had a crush on Grayson but he dumped her p badly. So she pretends to be friends with him while she waits for him to get his karma for being an asshole.

Wait is that girl that is pregnant the same girl who wanted to plan her revenge with Grayson or nah