Military??? Flight out of RFD?

This does not show up on any flights on the site. Today, at about 3ish there was a jet that certainly did not meet any Db level requirements…it climbed like a bat out of heck…the sound was thunderous, and I was about 20 miles from the airport. It looked from the huge distance to be a small fighter of some sort…anyone have any idea?

It can be a military jet and they cant track any military aircraft (few were by mistake shown). Or it could of been a old Turbojet type aircraft (Learjet 24,25,26 or a IAI Westwind 123 or Gulfstrean G2/G3 or similar).