I used a handheld fetal Doppler during my second pregnancy and it did give some reassurance between appointments, but I think it is worth weighing up both sides before you get one. The upside is that it can be comforting to hear the heartbeat at home, especially if you are the anxious type, but the downside is that if you cannot find the heartbeat you might panic unnecessarily, or worse, feel falsely reassured when something is actually wrong. Most OBs and midwives here do caution that it is not a substitute for proper monitoring at your polyclinic or gynae. If you do decide to get one, I would say check in with your gynae first and ask what they think, since they know your pregnancy history best.