Is a visible gray injection mark on lips normal after filler? (Photo)

I had Teosyal injections 12 days ago and all the other injection marks healed quickly. The next day there was only little visible bruising and swelling. This was my third filling, last times with Juvederm and there were no such marks from those. But now I noticed that there is a little gray bump on one of the injection spots. It's relatively small so I hadn't noticed it before, but with a closer look it's clearly gray and feels like a small pimple. Is this normal or something to worry about?