I was in hospital for a week last year with cellulitis - my right leg from the knee downwards swelled hugely and was very severely reddened, hard and inflamed. At one point it was around twice the width of the left leg, and I had a high temperature for days. It took three different antibiotics, two of them intravenous, to shift it. It healed, but left discolouration and a poorly-drained thick ankle. It wasn't, in my case, caused by a bee sting but I can certainly vouch for the unpleasantness of it. If you get it, be prepared for alarming symptoms... it's rare but not that rare. A basic local infection of a sting is commoner (unpleasant but a lot less dramatic).
I'm not allergic to stings, but I gather that if you've really only ever had the one, then any allergic reaction would happen from then onwards, i.e. once you had been sensitized by the first sting. So you might want to wait a while before relaxing and taking the gloves off...
Personally I find that stings vary enormously from mild nettle to red-hot nail, and from days of infuriating itching to a few hours of redness. The bee, the length of time the sting is in place, my own state of health at the time, and the position of the sting, all make a difference. I've heard that aspirin, nurofen and similar drugs can occasionally provoke a bad reaction too, although I've never experienced it.
I've only once had a really bad experience, which was about 40 stings at once, fortunately through trousers. This was enough to cause some toxic effects, and left me feeling groggy for a couple of days. They weren't actually bad stings though, and after two days it was more as though I'd walked through a nettle patch. These are usually reliable bees, it was a mistake on my part that caused the aggro... but you should always be prepared for accidents. Anyone who (aaagh!) has ever dropped a frame or, worse still, a box, could tell you about stings I'm sure...
