I agree with bny. You probably ovulated before your IUI, but since the egg can live for up to 24 hours, and the sperm specimen is placed straight into your uterus, you still have a chance! Best of luck to you!
i've heard of dr's doing two at 24 and at 48.. and it working! : ) ovulation can vary, but typically it is around 36-39 hours after the trigger.. your egg can last almost 24 hours i believe and the sperm a day or longer once washed! good luck! : )