Fetal heart monitor

I bought a fetal heart to heart monitor thing so I can try to listen to baby so I stop thinking she's gone. I'm only 18 weeks and it's a third trimester one. I can't hear the heart beat but I hear what I think is lots of thumps and kicking. She obviously doesn't like it on my belly because she just kicks at it lol. I'm glad I can't feel those kicks yet cuz the way she does it is pretty intense lol