I take pregnancy test they are negative but no period and brown discharge

Tests are accurate: Today's home pregnancy tests are very accurate and not affected by foods, herbs, common illnesses, sexually transmitted diseases, or medications. A urine test will give a reliable result by 3 weeks after sex (3 weeks after when conception might have been) or 1 week after missing a period. If tested sooner, a positive result is likely real, but a negative result may be due to testing too soon.