The accuracy of the Coriolis pregnancy test is very high and can be as high as 100 percent, as long as it is used correctly and the test is not expired or damp. However, it is important to note that the pregnancy test is only used to check if you are pregnant before the day of the test. If the pregnancy occurs later due to ovulation or late implantation, it is not that the pregnancy test is inaccurate, but that the HCG level in the urine at the time of the test is relatively low and has not yet reached a level that can be detected by using a pregnancy test. So it’s best to take another test three or five days later, and it’s recommended that you don’t drink too much water before the test to avoid diluting the urine.