Motorcycle ride seems not so smooth?

I have an 08 Kawasaki Ninja 250r and I am fairly new to riding so I would appreciate an experienced person to let me know if this is a problem or not. While riding my bike on straight a ways at about 45+ mph I noticed the ride isn't perfectly smooth... almost a little bumpy, but the road doesn't appear bumpy or majorly uneven. I also noticed when I pull the clutch and or brake the ride seems to be nice and smooth. Is it normal to experience the a slightly bumpy ride while pulling the throttle? Answers, advice, and opinions all welcome. Thanks for your time!