You can take a pregnancy test about 5 days before your expected period, preferably using your first morning urine. Make sure to check the instructions on the test box, as different brands may have different recommendations. Taking the test too early can increase the chances of getting a false negative result. If your periods are irregular or if you are unsure of your cycle, you can take the test about 14 days after unprotected sex. If you still have doubts after a negative result, you can retake the test about 3 days later, again using your first morning urine.