Timing of IUI

This past cycle I used clear blue ovulation kits. I got a + on 9/21 at 5am. At 9pm that night, I had right sides cramps that were obviously from ovulation. I had my IUI the next morning (9/22) at 10am. I have read that the egg can only be fertilized for 12-24 hours. Does this mean that my IUI was too late? It seems like we could have missed the window that the egg was viable.