Babies moving or gut feeling?

I'm a first time mommy and am currently 16w5d expecting twins. I'm having a hard time sleeping right now and it's because of this feeling in my stomach. It feels like that gut feeling when your SO may be doing something bad lmao but he's asleep next to me..or that anxious feeling when you have to talk in front of a big crowd but you have stage fright.. Is it the babies moving or is it something else?