Can you get a bug that just makes you feel achey and buggy with no other symptoms?

[Heliotroping]

Just that, really.

For about 3 days I've felt like I have a bug - achy head, back, and sensitive skin, but no sore throat, sneezing, nothing

Can this be a bug, or more likely something hormonal, etc?

TIA

Have you got a temperature?

Just wait!

Have you been out in the sun? Is it not just a bit of dehydration/sunburn?