Ay mami, yan ay totally normal lang! Babies do that in the womb kasi they're practicing their reflexes, swallowing, breathing movements, lahat ng ginagawa nila to prepare for life outside. A few of us moms noticed the same thing sa ultrasound namin, at super common lang talaga yan, nothing to worry about. Next checkup mo, you can ask your OB just para peace of mind, pero honestly alam ko na sasabihin niya na okay lang yan hehe!