Could The Positive Pregnancy Test Be Due To Postinor Not Being Effective?

hello I had sex on the 7th an I took postinor an still had sex on the 8th I took postinor on the 9th an my period was to come on the 26, 27 but didn’t come then I later had some light flow on the 28 Till today the 31 am still bleeding And I did a pregnancy test on the 30th it came out positive please I don’t know am confused is it that the postinor was not effective or should I wait an do the test again