Why is my maintenance required light on?

just over a month ago i bought a 2005 scion tc with 91000 miles. just a few days ago the maintenance required light went on. i did my research and everything i found said that it meant i needed an oil change. i'm still about 1500 to 2000 miles away from when it says i need to get my oil changed. i know how to reset the light but i wanted to make sure i dont need to get an oil change before i do that