pain in cainine tooth

Hi
I'm in my 40's and had orthodontic brace treatment last year (removed in Dec 09) with very pleasing results.  My teeth are in good shape, I take great care of them, wear my retainer etc etc.

Also, as a back ground to this.  I've had a very nasty cold which I'm still getting over - very sneezy and chesty and I've had a couple of nosebleeds in the past week.

In the last three or four days my right cainine tooth is getting heat sensitive and its tender right up in the root area near my nose.  In fact it feels like the two are connected - its the nostril I've been bleeding from.

Theres no swelling and no actual pain, just a growing tenderness and sensitivity.

I know it could be to do with my cold, but I'm worried.  Firstly because I had a dental abcess (abscess) years ago and I'm still traumatised by it.  Secondly (yes I'm being a hypochondriac - but its not cancer is it?)
More practically I've just spent £3000 on my now lovely teeth and I don't want it ruined!  Help!