I recently stopped using Micronor because it made me very dizzy (to the point of my vision blacking out almost every time I stood. I have been using condoms and I BELIEVED they worked fine the first 3 times, But on the 4th time it slipped off inside of me after my boyfriend ejaculated. When this happened I was already late for my period (possibly post pill amenorrhea?). I took the Next Choice emergency contraceptive pill 4 hours after the condom failure. The NC box says to take a HPT if your period is one week late. The only symptom of the NC pill I have had is slight nausea last night. Since I was already late, when should I take a HPT to make sure i am not in the 12% that still get pregnant after taking the Next Choice pill?