Carlos,
You’ve been under a lot of pressure and stress which is understandable. Maybe you’re getting cold feet. That’s a huge responsibility to have and raise a child. It seems you love your current girlfriend and the ex is just an escape from the pressure? The sex could be great, but sex doesn’t make a relationship. Think of who chooses you. The ex who isn’t always available or the girlfriend that wants to raise a child with you. That is love. She trusts and honors you enough to raise a human being with you. You deserve love and respect and so does your current girlfriend. We are human and none of us are perfect. We are all tempted and fail miserably at times. My vote is to get rid of the ex, it didn’t work for a reason. Maybe a new hobby? lol