my 4 month baby vibrates his head or leg sometimes, has happened twice or thrice till now and remained for 2 3 seconds and he's very normal during and after vibration. playing well and having good feed. having calshine p .5 ml once a day and a to z syrup 8 drops twice a day. I am on medication of levera 500 mg during pregnancy as well and now also but having no seizures till 4 5 years. is this vibration normal in my baby or anything to worry about .