Hard lump post root canal retreatment

[cinnamongym]

Hey there,

I've been searching around the internet trying to find an answer to my problems, but can't find much about it. Hoping someone on here can help me.

I had a root canal on #14 in 08/11, and around 12/11 I noticed that there was some pain above the tooth, but I couldn't tell if it was coming from my sinuses or from my tooth, and I didn't do anything about it thinking my immune system will take care of it. It wasn't until 05/12 that I actually stuck my finger up in my mouth where I had the pain and I noticed there was a very hard, marble sized lump. I immediately called my dentist, who referred me to an endodontist. During the root canal retreatment he found a missed canal, and said that was the source of the infection, and now that the source of the infection had been cleaned the infection should go away, and over time the bump will disappear too. He also put me on antibiotics. The retreatment was done 4 days ago, and my last day of antibiotics is tomorrow. The problem is the bump is still as large and painful as before. I've never had any drainage into my mouth, and the bump is quite firm to the touch. It's incredibly tender to the touch.

My questions are:

Do I still have an active infection, and do I need to go on another round of antibiotics or call my dentist for further treatment (apico)?

Why is the bump in my mouth so hard, as opposed to pus filled/pimple like?

I'm concerned that after a root canal retreatment, and a full course of antibiotics, there is no change in the size or pain of the bump.

Thanks in advance for any advice.