Rapid Covid Test Faint Line. A doctor has explained why seeing a faint second 'positive' line on a lateral flow test doesn't always mean you have the virus. Getty images) the fastest way to currently find out if you are covid positive is to take a rapid lateral flow test.
We need to assume that if there's a faint line. However, if the “positive” line is very faint and appears after a certain amount of time, it could actually mean you are not infected, a doctor has said. Growing rapidly in the uk.