I'm a FTM and since 16 weeks I've felt my baby boy move daily, a lot, at first it started out as little bubbles popping and then by week 17 it felt like a fish flopping around, he moved constantly during the day.. I'm now 18 weeks and since yesterday I haven't felt him move once.. I have an at home Doppler and I've found his heart beat but it seems like it's more distant, kind of hard to hear but I can hear it if that makes sense, whereas last week it was very loud and sounded like I was right on top of him.. is this normal?! Should I call my doctor?