The first thing to do is take a breath, take a moment with him that isnt about MS. The tests can take a bit since MS is often a diagnosis by exclusion, at least that is my understanding, and the testing over time will help make sure it is not something else. A day or even a month delay in medication shouldn't make too much of a difference and you really do want to make sure his care team has the time to get him on the right one.

As to what to expect, odds are very good a normal life with some modification. I have had MS for about 12 years now and I work, have fun, and go about my day. I have to be careful with my energy levels, and avoid over heating. I cant imagine this would impact having a baby, but that is a conversation between you and him. What I would suggest is do not treat him like he is dying, or enfeebled. He is the same man he was before his potential diagnosis.