It was swine flu after all. The woman who infected a load of people at work was lying when she said she'd been tested and it wasn't swine flu. Someone else at work who passed it on to their asthmatic kid had the test done, and the child tested positive for H1 N1. Great.
As soon as I realised I wasn't well, I stayed home, but I spent a day or so in the office feeling strangely tired, and one of my workmates is on immunosuppressant drugs for a longstanding illness, while another is asthmatic. They've all been exposed to my boss, and are still fine - the incubation period is quite short, so I don't think I've infected them.
All I can say is, it's not as bad as ordinary flu - if you're a healthy adult. The dogs behaved beautifully, they understood I wasn't well. My sister posted groceries through the letter box, I quarantined myself for five days, and now I'm fine. It's odd having flu in summer. Glad that's over.