<s>[INST] Hi doc..My wife has missed her periods by 2-3 days this month..we had an unprotected sex on 22nd may 2013, she took an i-pill on 23rd may 2013. Her period cycle is of 28th every month..today morning we had tried CIPLA PregTest that came negative (Only 1 pink line on C). Can i-Pill delays the periods? By how many days approx? Is she pregnant? [/INST] Hello, Taking I-pill within first 24 hrs of unprotected sex gives protection more than 95% against unwanted pregnancy. Following taking I-pill, period may be delayed for 7-10 days in general. It occurs due to hormonal imbalance and mental stress. You did sex mostly around safe period and got negative pregnancy test. Here, she waits another 1 week to get period normally. Otherwise, consult with gynecologist for proper medication to induce period. Take healthy diet, Chat Doctor.  Be well & practice safe sex in the future. </s>