When to do the test, each woman has the right to decide for herself, but you should know when the test shows an accurate result.
After a delay.
Most test strip manufacturers claim that you can do the test from the first day of the delay. In most cases, this is true, but for a more accurate result, you should start doing a test for 5-7 days from the day of the delay. The result will be shown as two bright bars or one bright and a second weaker one, depending on the sensitivity of the test.
Until the delay.
Many women can't stand it and rush to take the test before the expected period, buying highly sensitive models that have a much higher price than less sensitive counterparts.
However, not all highly sensitive tests can give a result before a delay, since the countdown starts from the day of ovulation, and if ovulation was late, then the test should be performed only a few days after the delay.
For example, a girl whose menstrual cycle is 28 days does a test on the 22nd day of the cycle, then even the most sensitive test will not give a result before the delay, since the hormone in the blood is not yet produced in the right amount at that time. The minimum period at which the test can show a weak second strip is 25-26 days, however, this also depends on the day of fertilization.