Most "early response" pregnancy tests say that they give fairly accurate results up to 4 days before your missed period. It's best to know your cycle and your body to know whether or not you're "late." They're pretty accurate. If you want to know for sure, it's best to wait until your first day of your missed period. It's pretty difficult to get a false-positive. If you really want to know, see your doctor and have a blood test done. Hope this helps.
