I received 2 positive urine pregnancy tests followed by negative blood test. period still has not come and pregnancy symptoms are persisting. could i still be pregnant?

Impossible with those negative urine and blood tests. Your symptoms could be related to the hormonal imbalance which can explain the late period.

Both urine tests and blood tests detect levels of hCG which help determine pregnancy status. Blood tests are 99% accurate and can detect very small amounts of hCG. Timing of the tests is critical and that was not mentioned. A missed period is usually the first sign of pregnancy.