I think it's a battery problem.. don't you ?

[jorizk]

Hello fellas :) How are you ?
Since a while a go I was cruisin in my 2006 yaris sedan, when I parked to get my friend. I left the radio and the lights on (low beams + fog lights) for like 7 or 8 minutes but the engine was turned off. Now when I pushed the ignition switch the engine would not turn on. Same things after a couple of tries. Then I turned off the lights. I tried once more, the engine started, but the starting phase (the part when the electrical motor does the work) seemed slow and hard on the car.
The thing is that the battery is stock and of course it must last more than three years:S What should i do ? Should I replace it ?

I would appreciate your suggestions.