In your dream you are trying to hide from your ex and his girlfriend. I can certainly understand this action, because such meetings can be very awkward, but it doesn't go like that at all. With that and the tone of the second dream, I think I know what's going on here.

When he moved away, I suspect that this broke off most, if not all, communication. But you had spent eight years with him, and still feel close to his family. This must have felt as if you lost a brother, as well as a boyfriend.

When you heard that he was going to be a dad, this put thoughts of family into your mind. Even though you don't feel ready to be a mom, you might be ready to be an aunt. You don't want to sabotage your ex-boyfriends new life - but you would still like to be a part of it. Just not the same part you played before.

Your recurring dreams seem to be saying that you feel that this is possible. In fact, it may be inevitable. They are sure to bring the new baby to meet family, and given that you are close to the family, you're likely to be included in this reunion. I think you can manage this without it being awkward, and without the past coming back to life for you.