I used this throughout the entire second half of my pregnancy and I loved it. I dealt with some anxiety throughout my pregnancy and being able to listen to my baby's heartbeat in the mornings and at night in a healthy way gave me wonderful peace of mind. I started to be able to hear the heartbeat faintly around 19 weeks but it really started to sound stronger around week 21. You do need to be in a quiet room and make sure that you are only touching the chin rest or else it won't work. The fetal heartbeat sounds like a muffled watch ticking quickly, you can tell the difference between your own heartbeat and the baby's because the baby's will be about twice as fast as yours. The added benefit of using this fetoscope to listen to the baby was that it allowed me to become very familiar with fetal positioning, as the heartbeat can only be heard when the fetoscope is placed directly over the baby's chest or back. By listening and feeling for different bumps and movements I was able to accurately judge how the baby was positioned and use exercises and chiropractic care to ensure that baby was head down and anterior in preparation for delivery.