On bc pill. week before period had sex. light bleeding for 5 days as period. implantation bleeding? took preg test today(19 days later) with fmu and neg, accurate?

Pregnancy unlikely: Home pregnancy tests are very accurate and not affected by foods, herbs, common illnesses, sexually transmitted diseases, vaginal spotting, or medications. A test gives a reliable result 3 weeks after sex (3 weeks after when conception might have happened) or 1 wk after missing a "period". If done sooner, a negative result may be due to testing too early such as less than 2 weeks after conception.