How long do you have to wait after the first day of your missed period to take a pregnancy test?

No: The morning after pill which is otc may delay a little but will not stop it.

Pregancy testing: While I am not an expert in this area, i think a woman should wait at least one week after a missed period for a pregnancy test to be most accurate. Also, it is best to do the test first thing in the morning, as this is when your urine should be the most concentrated increasing the chances that the test will detect the pregnancy hormone, which is called hcg. Good luck.