i had sex with my boyfriend few days ago, and we didn't use a condom, but he didn't ejaculate. Just for safety, i took an i-pill within 2 days. The very next day we again had sex in the same conditions, where he didn't ejaculate, and i was supposed to have periods in a day or two, which got delayed by 3 days, and now finally i had periods which lasted only for 2 days, whereas usually my periods used to last for 4 days. Could i be pregnant? After how many days of sex can i use the self pregnancy test (through urine) to get the right result?