No, it’s symptoms of a cold.
It's the symptoms of being run down, which often results in a cold as your immune system is weakened. If you're tired or you've overworked your body, you're going to be sore. If you're stressed you're going to have a headache.
BTW, I've just done and done a 50k ride. While I was out I felt a started feeling like I was getting a cold (from when I was younger I had an ear problem so if I even start to get a bit of a sniffle my ears absolutely kill, they always have and always will). So I've done a lateral flow - it's come back negative, though the mucus on it was pretty horrid after I'd put it onto where my tonsils would be. I also did a lateral flow yesterday (when I felt fine), as I was going out for a meal with the work lads.
I'm not against your idea of testing, I'm just saying it will always rely on people. I don't have anything to do today that relies on me going out but you know. If we didn't currently have a spare box of LFs I probably wouldn't have wasted one but I thought it better to be safe than sorry.
What's the difference between me doing this, and going to record my result, than someone else having to come out to someone's house but in the meantime that person has to isolate for however long that takes to then get the results back.