I have clear lump 2 weeks after fillers, is this a blister or ulcer? (Photos)

Given how well formed the lump is, it is likely to be a granuloma. (an inflammatory response to the filler) These can be more common if the injections are given too superficially - which should never be done in the lip area.
If this does not improve quickly, you will need to consider either a steroid injection to filer dissolving injections.

This might just be a collection of the filler which was injected too superficially. Either making a nick and draining or hyaluronidase should resolve this problem. 

Dear Victoriakearns87:In these photos it appears that you have a small collection of filler very close to the inner mucosal surface of the lip. This could easily be nicked and expressed after a little topical anesthesia, which will not be uncomfortable for you. Alternatively, hyaluronidase can be injected.In the future, a filler will low cohesivity that spreads like honey, such as Belotero or Volbella, as opposed to one that sticks to itself, and injections in very small aliquots  less deeply in the lip will avoid this.I recommend you seek treatment with an advanced injector who is a board-certified physician in the fields or dermatology or plastic surgery. Knowledge of the anatomy of the lips and the physics behind the rheologic properties of the various fillers is critical to a successful outcome without significant complications. For example, the labial artery, which is located more deeply in the lip than where fillers are normally placed, must be avoided to prevent lip necrosis and other problems.All the best,  Dr. Clark

This may be an accumulation of filler. I would gently massage the area and if this doesn't improve the situation then see your injector. You may need to have the lump dissolved. Best of luck.

Thank you for your question and photos.It may be some product that has formed a lump, if the acyclovir is not improving the nodule.  You can massage the lump or have hyaluronidase injected to dissolve the collection of product.  Regardless, it is best to follow up with your injector.Best wishes,Dr. Kavali

Like others I think its a small area or filler placed superficially and easily treated by your specialist injector. The other thing to consider is a cyst in this area. A clinical examination and a tiny nick or Hylase can tell the difference between the two. All the best, Dr Davin S. Lim. Brisbane. Australia.