Hi, Me and my girlfriend made out on the night of 1st of September, during making out my penis got in touch of her vagina opening, and maybe it had some pre-ejaculation fluid on it. First day of her last menstrual cycle is 23rd of August, and her cycle length is 28 days. She took Unwanted 72 after 68 hrs of it on 4th of August. I am too afraid, should I worry about pregnancy? And do these pills delay periods? And is it necessary to have withdrawal bleeding to know that pill has worked?