Had Botox injections yesterday for frown lines. I have redness and swelling above my eyebrows. What's the cause?

I hate to put it like this but as if someone gave you a punch in the face but only in a small area above your eyebrows! It doesn't protrude in a massive way but there is a area above each brow protruding. And there is noticeable redness as if 'something happened". Looking at my profile, it looks like I have a strong brow. I did not have any of this beforehand. How can this be reasonably explained? Is this rare and it is a permanent disfigurement?