Visited my gp and he sent me for a covid test as a precaution on what he believed to be a viral infection, my test came back negative but since then i have lost my taste and smell but i have no other symptoms. could it be a false negative?

False negatives: You could have a different cause for your taste and smell loss, BUT, your test may well have been inaccurate if it was a rapid or non-PCR approach. These tests may pickup only 50-60% of milder cases. The PCR is far more accurate.

Could be: Covid-19: https://www.cdc.gov/coronavirus/2019-ncov/index.html Please contact your doctor by phone for further evaluation and mechanism for testing in your area. Wear a mask, stay away from others, practice hand hygiene. Be sure to get tested, if you get more symptoms. If you develop breathing difficulty, go to the nearest hospital, immediately. Wish you good health.