They did a soy challenge at the children's hospital I was going to for DS, and when he passed (at a year old), a month later they did a milk challenge. He passed both. Caveat: at 18 months old he got a virus, and got both intolerances back, and he's had them off and on since, changing symptoms each time, so watch for ANY weirdness going on.
I thought DS "just" got red cheeks from soy, but it was doing something inside as well because it started waking him up all the time (10-12 times a night) so it's probably an indication of something.
If you have it then yes, it'll stay in your milk at least a few days so if he does have a reaction, he'll react for a few days at least. But if he has it, and hasn't had it before, he could have a reaction that's more than he had through your milk, if he still has it. Have you done any healing for either of you, or just the avoidance? I'm just curious, since I think that might have been my mistake in the first place. And I wish I'd known more then.
Also, it's an allergist that you're seeing, not a GI doctor? That seems surprising to me, since only one of the allergists I ever saw even "believed" in intolerances. Usually if it's not an "allergy", then they pass you on to someone else.
Kathy, mother of 3, wife of 1. My new recipe blog: www.kathysrecipebox.wordpress.com (no longer searchable by allergen, but at least it doesn't have a virus!)