Why did my warrant not show up when I got a ticket?

There are several different systems that they could run your name through for warrants. Either the jurisdictions you have been stopped in aren't connected or using the same systems (MULES, NCIC, REJIS, LYNX for example) or they aren't running you (which would surprise me!). I would hurry and turn yourself in to avoid you being picked up when it's "not convenient". Pick your time and turn yourself in!