2 days ago HA dermal filler was injected into my cheeks. The last injection caused immediate swelling and a lump. What is it?

At the last injection site (with a very small amount of around 0.1-0.2ml), the injection was made and it swelled up like a ball, tightening the skin -- much more than the injected product. There was some bleeding, but not lots. The area was red, which is has turned to just a pale red now. Will this go away? What could it be? Allergic Reaction? (It feels hard.) A large sub-dermal haematoma? There is minimal skin discoloration, just some redness and broken veins. Has anyone ever seen this before? My injector is very experienced but said she hadn't. Any advice? :)

No doctor answers yet