Can you use a pregnancy test kit four days before your period to check for pregnancy?

Patient's question:

The menstruation came on the 18th of last month

Doctor's answer:

Hello, generally speaking, pregnancy can be detected using a test strip about 14 days after cohabitation. However, in clinical practice, the use of early pregnancy test strips to check for pregnancy is usually determined by the delay in menstruation. It is recommended that you use a test strip to check morning urine after your period is delayed by more than 3 days. If it is negative, you should check again after your period is delayed by more than 7 days. If both tests are negative, pregnancy can be ruled out.