I had sex on 5/10 around 1am. We used a condom, but I found it inside me on 5/11 around 9pm. I took Next Choice at 9am on 5/12, and took the second dosage at 9pm on the same day. My period was due on 5/11, but hasn t come yet (7 days late as of 5/18). My last normal period was 4/10-14, and before that 3/11-15. Average days in my cycle is 31. My periods are commonly 2-4 days off (late or early), but now I m definitely worried. When at school (I m 20 and at a university) I spend lot of time around my teammates, who have succeeded in pulling me onto a different cycle then when I m home with my sisters and mother. I moved back home last week, could the shift to a different environment be affecting me? What are the changes that I m pregnant? Would I likely get an accurate result if I took a HPT today?