Chin up! This will hopefully prove to be nothing. If otherwise, then you will have caught it early, and that's good too. As far as WW - I should think this counts as a valid doctors excuse for not doing your normal routine. If you can find other exercises to do instead, that sounds like (at least mental) Extra Credit! Though I doubt that they'll officially notice that you went above & beyond the call of duty.
(note: i've never been in WW, so I'm clueless)
Also: I think if the doctors office thought this was a big deal, the doctor would have been the one to contact you. Try to be re-assured by the amount of minimalness they are assigning to the situation.