S for spine

Momshees, need your views on this please, baka na-encounter nyo na rin. Nung paliguan ko kasi si lo the other night, napansin ko yung spine nya parang nag-shape ng S nung gumalaw sya. At 8 months, he is now able to stand upright, roll, crawl, sit and cruise. But I am a bit bothered about what I saw. Should I have him checked by his pedia for it? Pa xray ko ba? Or is it something normal?