Hindi ka nag-aalala, normal lang yan! A few of us mums sa circle ko didn't feel movements till around 20-22 weeks, lalo na kung first time kang pregnant or kung front-facing ang placenta mo, it can muffle the kicks talaga. But just to be sure everything's okay, best to mention it to your OB sa next check-up, especially if may other concerns ka, they can do an ultrasound and put your mind at ease agad!