I appreciate your query.
The failure rate of emergency contraceptive
pills is very low, hence it is unfortunate that it failed in your case.
However, all recent studies so far have shown that pregnancies after failure of emergency contraceptive pills are safe.
There is no association between the use of emergency contraceptive pills and the risk of major congenital malformations, pregnancy
complications or any other adverse pregnancy outcomes .
So, do not worry about anything at this stage.
Have your ultrasound
at the earliest .
Also, take prescribed prenatal vitamins
, folic acid
etc, and abstain from teratogenic agents ( smoking, alcohol etc ) to reduce chances of fetal malformations.
All the best with your pregnancy.