Woke up this morning after a weird night (odd dream!). Since then I can't get warm, maybe getting a sore throat.
Haven't been out since Tuesday when I went shopping, although went to the gym yesterday and had a good workout (usually I struggle if I am going down with something).
Perhaps I am getting a cold, but where from? I thought they took three days to develop?
I've got a cold, and I was like you - I'd been out the day before, but not for a week or so before that. So it may this year's virus is quicker-moving than some.
Also you've obviously exposed yourself really fit bugs at the gym...