I'm 17 weeks and I hadn't felt him more in a day or so. I was worrying so I lay flat on my back and jiggled him around a little. Nothing happened. So I used this little heartbeat app I had downloaded to try and hear him, but still nothing. Finally I de used to play some classical music for him because I've heard they love to hear music. It helps with brain development and his little ears are fully formed this week! As soon as I held the phone speaker to my tummy he started kicking and bouncing all around!!! I definitely recommend!!!