My ex and his pregnant new girl that he's been talking to has been chasing me in my dream non-stop
Dreams about being chased are very common, and they often relate to feelings of anxiety, stress, or fear. In this dream, your ex and his pregnant new girl were the ones who were chasing you, which could suggest that you feel like you're being pursued or chased after by something in your life that is causing you anxiety or stress.
As for why your ex and his new girlfriend were specifically the ones chasing you, it's possible that they represent a particular situation or person in your life that you feel threatened by or feel like you're competing against. Alternatively, this dream could simply be a reflection of your own feelings about your ex moving on and starting a new chapter of his life with someone else.
Overall, it's important to listen to your own intuition and feelings about this dream. If you feel like there is something that you need to address or work through, it might be helpful to talk to a trusted friend or therapist about it.