Hey, if he's the perfect man, he will probably be feeling all the same emotions you are feeling right now. I would let him know while you are still crashing through all the emotions. Waiting until you are done dealing with them all means you will look calm and controlled and he'll be crashing through all the realities you are now dealing with.
why not deal with them together ?
My kids (from a prior marriage) were 10 and 12, when we got a surprise baby. The surprise baby was followed up with a second surprise 20 months later. It's a challenge, and all my friends are empty nesters, which we would be, too, if not for the 12 and 14 yr old, but it's WONDERFUL!!!
I admit, after the youngest was born, my husband had a vasectomy . . . but I was 41 at that point, and we knew our home was "full". I used to joke around and tell everyone that I made my own grandchildren - but you know what ? I wouldn't trade it for the world !
Sometimes life hands us challenges we weren't planning on having, but love grows and somehow we get through !