Follow up ultrasound on 2/9/18

Kristen

My husband and I always joked it was twins. My first ultrasound measured 7 weeks 6 days but showed one baby. I’m starting to show and get tired spells. I’m currently 9 weeks 2 days. My next ultrasound is in 2 weeks. Could it be possible that I am pregnant with twins but it didn’t show on the first scan? Has anyone had this experience?