It is very hard for anyone to say if they have the flu the symptoms are essentially the same as any cold, although typically worse. I have spoken to a few people who have lived through a flu this season and they basically had all the respiratory issues coupled with extreme fatigue lasting for days and a high fever. The stomach/lower intestinal issues are only a bonus for a lucky few.
Although they are not testing anyone to see if it is H1N1, if you have the flu you probably have H1N1 as it is the strain of influenza that is most common currently.
We ended up taking our 2 year old to the screening clinic on Sunday and then to Childrens for xrays, turned out to be pneumonia and not the flu. The ER Doctor that we saw mentioned that there are also a few really nasty cold strains going around.
In regards to getting the H1N1 shot after having flu the Alberta Health Services website states "People who get the H1N1 vaccine who have had prior H1N1 infection are not expected to have any adverse reactions." So if you are unsure and are high risk you probably still want to get it.
Lots more info for anyone who wants it:
Alberta Health Services