2000 Jeep Cherokee Hard to start when engine is cold

When my engine is cold (not the weather) it takes my engine 10 to 20 seconds to start up. The engine turning over is at a normal pace and not sluggish. After the first start up it will start up normally with no problems and it runs as smooth as it ever has. I had the battery changed today and that did not fix my problem. I've only had this problem for almost two weeks now, not long after a much need oil change. Any suggestions on what else the problem might be?