What happens after graduation? Will he get leave? Our wedding is July 7. Do you think he will be able to make it before he goes to flight training?
Following graduation, he will walk across the street and report to API. The first thing he will do there is complete IFS (assuming he doesn't have any civilian flight experience). That should take about 6 weeks if he starts right away. Then he will go through API. Chances are, he will be able to get a little leave for your wedding. Unfortunately, a definitive answer on that won't come until he is at OCS, and may not come until he is done with OCS. Most commands won't promise leave when they know the person requesting leave will transfer before the leave period. However, OCS may be able to coordinate something with API for him.
One major caveat, and this is one you need to become comfortable with right away since you have chosen to become a Navy spouse, he may only get a 2 or 3 day weekend to get married. Don't make any non-refundable deposits for a honeymoon trip.
My personal story. My wedding day was scheduled for 1 1/2 months after the scheduled return from a 6 month deployment. We were crossing the Atlantic on our way home when there was a crisis in Haiti and our battle group was on deck to support US ops well beyond our scheduled homecoming. My squadron was shorthanded and operational tempo was high. My CO promised my fiance (now wife) that I would make the wedding, but couldn't promise any more than that. My plan was to fly from my ship to Puerto Rico on Friday morning and catch a military hop to Jacksonville that afternoon. I had commercial reservations from Jacksonville to Washington DC for Sat morning. Rehersal and dinner Saturday. Wedding Sunday afternoon. Catch a commercial flight back to Jacksonville on Sunday night (after about 1 hour at the reception)

. Military hop to Puerto Rico Monday morning to a waiting helo back to the ship.
Extreme example, perhaps. And he's just going through flight school, not going to war. But the Navy may need him to start training without delay. The needs of the Navy take priority. Something you really should be willing to put up with while you are a Navy spouse.