Did your second baby get looked over?

I’m 9w 4d pregnant. I saw my doctor at 8w 2d and she didn’t look around after she found the baby, and there was only one. But I can’t help the feeling that there is a second baby in my tummy and she was in such a hurry she didn’t even look around. We also didn’t listen to the heart beat just a really quick ultrasound. Has anyone thought they were having one then the second was found farther along? I’ve read that i happens pretty often. I see my dr again on February 8th.