This is when a fetal pole, the first visible sign of a developing embryo, can be seen and throughout the pregnancy, your baby’s heart will continue to develop. But between 6 1/2 to 7 weeks after gestation, a heartbeat can be better assessed. That’s when your doctor may schedule your first ultrasound to check for signs of a healthy, developing pregnancy. A fetal heartbeat starts at between 90 and 110 bpm during the first weeks of pregnancy. It will increase and peak at around weeks 9 to 10, between 140 and 170 bpm.