Hi,
I-pill is effective in 98% when taken within 72 hours of the unprotected sexual intercourse, not after the expected date of next period.
I-pill is not a drug which causes
abortion, rather it is a drug which prevents the
pregnancy from attaching itself the the lining of the womb.
And since she has taken it after missed period there is a possibility that she is pregnant, please do a urine pregnancy test to determine. Doing
ultrasound too early in pregnancy may not help.
I-pill contains high dose
progesterone which can affect the fetus ,but the affect of
hormonal drugs on growing fetus is most after 6-8 weeks of pregnancy .
If at all your wife is pregnant, it is too early for it to be affected. Also I-pill does not affect male fetus, but can only cause some masculinizing changes in female fetus if taken between 6-8 weeks of pregnancy.
So, you could continue the pregnancy, if at all it is confirmed from the HCG tests and repeat ultrasound once HCG level reaches 1000.
Hope this helps.
Regards.