Enoxaparin (lovenox) injection site....scary lump!!

So I just started giving myself the injections a few days ago and today it immediately created a ball type swelling after my injection....

It’s not red or bruised.

My husband thinks it’s the medicine that hasn’t dispersed yet but it feels hard to me...

Is this normal? Is there a way to avoid this?

UPDATE:

It got worse and scary. BUT I called my doctor and he said this can happen and this probably won’t be the last time. He said I most likely hit a blood vessel and that the hard ball I felt was most likely blood and that I have a small hematoma.

Bruise pic here:

Swelling pic here: