Hello Dear, It is always advisable to use birth control measure before sexual intercourse. You might also not be knowing about emergency contraceptive pill. It is a pill that prevents pregnancy if taken as soon as after the unprotected sexual intercourse till within 72 hours. As 72 hours has passed, there is less chance it can have effect but the effects do not expire for as long as 120 hours. So take one emergency contraceptive pill (I pill, Plan B) as soon as possible. What you can also do now is wait for 3 more days and take a home pregnancy test. This kit is available in all medical and super stores. The instrutions are given on the pack to take the test. You have to urinate on the indicator area of the stick and look for (+) or (-) sign indicating positive or negative test, respectively. If it comes negative, you just have to wait for your menstruation. If it is positive, you should see a gynecologist to discuss further options. Do not worry excessively. There is always a way out of all the situations. But please take care in future. I hope this information helps you. Thank you for choosing HealthcareMagic. Best, Dr. Viraj Shaj