I picked up a nasty cold from someone I was sat next to on a plane. The cold has subsided, it's not as bad,  but I am left with pain on what feels like the left tonsil whenever I swallow.   Took it to the gp at three weeks,  they said come back if it's still going after it's been six weeks.   I have diabetes and I guess that can extend a cold a bit but it seems a long time to have a sore throat.   How can throat cancer begin? Feels like a long time till my appointment with the gp.