I think 1 mo may be pushing it. My youngest (now 3yo) had some medical problems that made it so we couldn't take her out of the house until she was 2mo. (She was born at the end of October, and her first real outing except for doctor's appts was the Christmas Eve service at church.) Even if s/he's perfectly healthy, at 1mo the two of you will still be adjusting to nursing, sleeping, etc.
It might be another matter if you live very close to WDW, and can go home if it doesn't work out (and if you don't have to buy non-refundable plane tickets.)
BTW, that youngest child made her first WDW at 5mo (by that time she was FINE), her second at 23mo, and her third just after her third birthday.
If I were you, if it turns out you are pg (!!!!) I'd start making plans for a spring trip.