Yes, sickness and diarrhoea is part of it. I am sure I had it several weeks ago, although I wasn't tested, didn't even see the doc. It took me several weeks to recover actually. Hope you feel better soon.
The GP can do a nasal or throat swab and then on the spot determine whether it is influenza A or B. If A they can sent the swab to the lab, will take up to 10 days before they can confirm whether it is swine flu though. However, if you test positive for influenza A there is a chance that indeed it is swine flu and tamiflu needs to be started within the first 48 hours in order for it to work hence the on the spot testing. However, totally depends on the GP whether they do this or not - many don't like prescribing tamiflu so are more likely to say 'it is a virus' (all flu is caused by a virus after all as are colds ...) and leave it at that. Hope you get better soon but if it is real swine flu it might take many weeks before you will have your strength back.