Preventing an unintended pregnancy : I Wanna Know - What to do after unprotected sex Like 95.88% | 919 votes Views: 143 25 Download Within 72 hours. Or, within 5 days. Get an IUD. Categories: Milking table Comments: Add Comment Cancel By Nakree - 22:22 2 weeks later. Get an STI check. By Zuluzahn - 17:49 Weeing soon after having sex will help flush out any bacteria that you to wait three two weeks after having unprotected sex before you take a. By Tojashakar - 09:02 If you had sex and are worried about an unplanned pregnancy, it's not too late. You have several emergency contraception options. By Samugul - 02:06 These types of emergency contraceptives are most effective when you take them within 72 hours of unprotected sex, but you.