I'm really worried plan b won't work. I did everything right. took it within 12 hours. I took it on the 24th of July, after my period had ended (23rd). My period app said I start ovulating the 26th of July and that I wouldn't be fully fertile until the 31st of July. My period was supposed to be here August 15th and here i am, August 19th, and still no period. I'm so worried.