Well, that must have been a shock! Dropping by at midnight and now what. That's really a shame that he couldn't ask for more time and attention from you instead first.
Ok, I'm reading your story a few times and how you love this man and are thinking of having children with him. Also trying to picture the boundaries, since he's your boyfriend and also he's your ex now and he has an ex who is possibly no longer his ex and how you and your own ex talk every day.
Well... I would say that in relationships it's not good to hit people; for one thing people can hit back. And in my opinion no Other Woman is worth fighting over ever. We womenfolk have better things to do, and if you show up and she is there, you can say "Oops, sorry wrong house" and leave with your head high. Also if you plan to visit anyone at midnight it could be useful to telephone first especially if you are concerned about giving him enough time to study.
What do you and this man share in terms of a life dream?
What were you both put here on earth to do? How can you do it better together than you ever could apart? What do you love about his character? What tells you he will be a good father to those children? And while he is getting his MBA, what life goals are you pursuing yourself while he is busy planning his future?
It is maybe unfair to ask, since those are very hard questions. The one good part is that you get to forge the answers yourself no matter what his plans are for the weekend. You also get to swap ideas with us here on this forum, because folks are listening and are interested in this relationship stuff.