Discectomy post op swelling

Hello, I am 15 days post op from a discectomy at L4/5. I initially did ok for the first week and when i had my dressing checked on day 7 by the practice nurse said everything was healing fine.

On day 10 I developed a painful swelling above my incision, approximately the size of a small orange.

I attended my GP on day 12 who agreed that I needed to be seen by my neurosurgeon. and whilst waiting for this I attended AE on day 14 due to the pain and swelling. They ruled out any immediate infection and said i was ok to wait to see my neuro on Tuesday.

I wondered if anyone else has experienced this after surgery and what or if anything the treatment is.

Many thanks in advance for any help.