If you have missed period and have had unprotected sex during the fretile period then the chances of pregnancy
might be there in you as per your symptoms.
The urine pregnancy test may be falsely negative during the early cases of pregnancy due to low levels of hcg
in urine and in that case the test should be repeated aftera week.
You may have the repeat urine hcg test done after a week to know.The blood hcg test is more confirmatory and can be tried as it is more sensitive than the urine hcg test.
Let me know if you have any doubt.