Sleep Walking... - Matthews,NC

My son is 2 years old. He's a great sleeper (when he eventually falls asleep) but in the last month or so we've noticed a trend, not every night, but most nights since he has been in his toddler bed, he'll get up at various times during the night. Sometimes I think he moves around so much that he wakes himself up and gets up. But other times you don't hear him at all until I hear a muffled cry or his footsteps walking across the floor. More often than not I wake up at various times during the night to find him curled up on the floor beside our bed sleeping on our extra pillows we throw on the floor at night. At first it was cute, we found him one morning sleeping in the dog bed and another morning sleeping on my husband's side of the bed on his pillow, more often than not he comes in with no sound and falls asleep on the floor. If I happen to hear him, my husband or myself will either walk him or carry him back to bed, only to find him back in our bedroom when we wake later. The gate at the top of the stairs secured and all chemicals are hidden and locked. There is nothing the can get into that will hurt him. The laundry room is closed, the bathroom toilet area is closed and all the cabinets have locks on them. But I'm worried that he is sleep walking. I know at 2 years of age, their imagination takes off and they start having dreams (some have night terrors) but is this normal? Is this a phase? What did you all do with your kids if they did this? Should I be worried?

Thanks,
A. B