I'm measuring big for eight weeks. I'm measuring big for eight weeks. You could be although the most common reason for measuring larger than you should is that your conception date isn't what you thought it was. If you're measuring large, you'll probably have an ultrasound to determine whether your estimated due date is correct and whether you really are carrying twins. The other signs of twins are a sizeable weight gain early on, or more than one heartbeat being heard.
Most people find out the news that they're carrying twins at their first ultrasound scan.
Until modern techniques such as ultrasound became a part of antenatal care, most women didn't learn that they were pregnant with twins until they were in labour. But such late surprises are rare today. People typically discover they're having twins during a routine ultrasound, often in the first trimester. Ultrasound is almost foolproof at diagnosing twins, but the greater the number of babies, the less accurate the ability to detect how many there are. You might not find out until the babies are born.