They started on your lips? Could it possibly be cold sores?
In any case, if you pop them, you need to MAKE SURE that the liquid doesn't touch any other part of your skin. Even if they pop on their own, take care to dab the spot with tissue, and wash your hands thoroughly after that. If it's a cold sore or a similar virus, it is sooooo easily spread around the skin. You don't want your entire face to be covered by the time your appointment arrives.
If it is indeed cold sores (you can google this and see if your symptoms match up, look at pictures, etc), there's a wonderful cream called "Abreeva" (one or two e's, can't recall) that you can get at any drug store.