Is this ok?

My son is 8 months old, and just started scooting around today. He lays on his tummy, and pushes himself forward with his feet, and pulls with his hands. However, he only pushes with one foot. Is that ok, or could something be wrong? Is this just because this is his first day learning? He can kick both legs equally well, and everything else seems fine, but I was just wondering if anyone else's little scooters do this?