My sister's last period was on August 3rd. This month, she missed her period, so after a week, she took a home pregnancy test and found out she is pregnant. After 3-4 days, she went to the doctor, who recommended an ultrasound scan. She went to the scanning center and had the scan, but at 4 weeks and 6 days of pregnancy, the baby's heartbeat was not visible. Is it normal for the heartbeat to not be detected at this early stage? Is it okay to have a scan at 4 weeks and 6 days? I know sometimes the heartbeat might not be visible so early, but when I was last pregnant, I had my first scan at 10 weeks. Typically, the first scan is done between 8-12 weeks. Why did the doctor recommend an early scan? Could there be any potential complications or reasons for concern?