No pain, I would say yay! And enjoy the pain free period. It's much more pleasant than cramps and backaches.

As for it being light, it may just be because it just started. I know for me, mine usually starts very light, gets very heavy, then goes back down to light. Its normal for flows to vary. Don't be surprised if it gets heavier later. Although sometimes periods are just light. There's nothing wrong with that either.

It might even just be spotting.