My period is 19 days late with 3 negative hpt. is it possible to be pregnant anyways. symtoms are nausea, lightheadedness. help?.

No: A urine pregnancy test done correctly gives a reliable result 3 weeks after sex (3 weeks after when conception might have happened) or 1 week after missing a period. That means 19 days late is long enough, so the results are true. If done too soon, a positive test result is likely real, but a negative result may be due to testing too soon, and therefore lead to a repeat test.