You know sometimes a person can just ruin a relationship from worrying about something that might not ever happen. Please try to think of the positive things and all that could go well. The main thing is good communication, trust, and respect each other. You get those down pat and talk to each other instead of holding things in, you'll do great. Please stop worrying. Don't let your mind go there. This can create problems within the relationship, for sure. This can create insecurity in both of you so please stop this negative thinking. I wish you the best, and congratulations.
