Ay nak, if your baby is doing something unusual with their body like that, please take them to your pediatrician or the nearest clinic as soon as possible, better safe than sorry, lalo na with babies. I know it's scary when our little ones do something we haven't seen before, pero the doctor can check properly and give you peace of mind. A few of us moms have been through confusing baby moments din, at lagi the best move is to get them checked out right away. Keep observing kung paano siya, at note down when it happens para ma-tell mo sa doctor. Sending you strength, mama!