My pregnancy test is negative after 22 days since the last time i had sex and 6 days after missed period. should i still be worried?

It's pretty unlikley: but there is some failure rate on the over the counter tests mainly due to mis-reading it--they can be tricky! the serum / blood test therefore has a very low failure rate. and would be positive by 10 days past a missed period.

No: If you last had sex 22 days ago, and your pregnancy test is negative, then there's nearly a zero percent chance that you are pregnant. Likely there's some irregularity to your menstrual cycle accounting for lateness in period. good luck!