You can take Unwanted 72.
Just remember two things;
It is quite possible that your wife might not have conceived . So you will be happy about the efficacy of the drug for no reason.
The treatment may fail. So if she is
pregnant, the pregnancy may continue. This point is important because so many women will have irregular periods when they are feeding their babies.
Whatever happens now, for future please ask her to use Intrauterine Contraceptive device.