With today’s modern urine pregnancy tests, it seems you can take them earlier and earlier. The box would have you believe by the day of your missed period. This really does depend upon when implantation happened and how much hormone HGC your body is producing. You should be able to take one the week of your missed period and get your result. Should you get a negative result for a week after your missed period and you ‘feel’ this is wrong, make an appointment for a blood test with your doctor to ensure the proper result. It will be more accurate of the timing as well. Good luck!