Women usually discover they’re having more than one baby during a routine ultrasound, often in the first trimester.
Your doctor will probably recommend an ultrasound in your first trimester if you’re unusually large. The most likely explanation is that you or your practitioner miscalculated your conception date. The ultrasound will help you find out how far along you really are and if your size has something to do with you carrying twins.
If you’re pregnant as a result of a fertility treatment, you’ll probably have an ultrasound within the first eight weeks to count the number of embryos. Ultrasound is almost foolproof at revealing multiple pregnancies, especially after 6 to 8 weeks. But the more babies you’re carrying, the more difficult it is to spot them all.
