Doesnt work enough

I heard my own heartbeat fine to test the app. Then when I went to find my babys heartbeat (Im due in 4 days) nothing. So hes big enough to catch a heartbeat. I heard something maybe...not sure. It was so faint I couldnt bet my life on it though if I had to. I am asking for a refund. If it works I shouldnt have to strain just to hear it or Psych myself into thinking i hear it....my final thoughts....doesnt work well enough to be sure youre hearing a heartbeat.

CuteLilMeeh about Fetal Heartbeat Monitor UnbornHeart - Microphone Baby Heart Rate Sound Stethoscope