This is known as the most sensitive early test out there -- and several scientific studies have confirmed it. The maker of the FRER says it can tell you you’re pregnant about six days before your expected period -- but pregnancy hormones might not be abundant in your system yet (everyone’s different!), so it’s only 68 percent accurate at that time, according to one clinical study. The accuracy increases the closer you get to your expected period.
Not all pregnancy tests are created equal! Some can estimate how many weeks along you are, some read "pregnant" or "not pregnant," some just show lines...Here's a ranking of the top 6 home pregnancy tests from The Bump.