The chances are good that the final cross-match will likewise be O.K., but it is not a sure thing. But keep in mind that the possible option fow a "swap" is still there is the final cross-match is bad. (In a "swap" you give your kidney to someone else in a similar situation, and that person's incompatible donor gives a kidney to your intended recipient.) Also in SOME cases plasmapheresis can be used to remove from the recipient's blood the stuff that would react badly to your donation, so the donation would be delayed but not cancelled.
best wishes,
Fr. Pat