What is this mysterious bump?

I was getting ready to go to The Wine Loft with Kayla last Friday night when I noticed a large bump on the back of my calf.

Mysterious Bump: Day 1

I ruled out the idea that it may be an ingrown hair because I've had those before, but never this big. Then, I panicked because I was finding spiders all over my apartment and thought it could be a dangerous spider bite.

I called an urgent care nurse to describe the bump and she told me not to chance it and just go to the E.R. I started to drive to the E.R. after texting Kayla the above picture. Her fiance Pete is a doctor, and, after looking at the photos, he said he thinks it could be cellulitis, which is a common infection of the skin and the soft tissues underneath. It happens when bacteria enter a break in the skin and spread. The result is infection, which may cause swelling, redness, pain, or warmth. Here are some pictures of the progression of the bump:

Mysterious Bump: Day 2 

I texted Kayla a picture once a day because I didn't want to go to the hospital and I wanted to sleep at night. Bless her heart, she made me feel better about it and told me to keep it clean and wait it out.

Mysterious Bump: Day 3

 

Mysterious Bump: Day 4
Mysterious Bump: Day 5
Here is what it looks like today.

I have yet to go to the doctor but I have an appointment next Tuesday.  I NEED YOUR OPINION. I would like to sleep well tonight...Please comment below if you might know what this bump is!