No. Most home pregnancy tests are effective only after implantation has begun. If this process has already started, the Escapelle/Postinor pill will not be effective.
Pregnancy tests are designed to detect the presence of the pregnancy hormone (HCG) in your body. If you’re pregnant, the amount of HCG in your body rises rapidly in the early days and weeks, and a home pregnancy test can detect this in your urine. But this does not happen within 72 hours after sex.