Is it possible that u could still be pregnant and have negative blood test? there are so many ladies online who say yes..i'm confused

Pregnancy unlikely: Today's 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 (or when conception might have happened) or 1 week 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.