I might sound crazy

I think my family even thinks I'm just hearing things. But twice now my five month old has said mama. When she was crying. Both times she woke up and I wasn't there (doesn't happen a lot because we cosleep) so she was scared and crying and said mama very clearly. I'm not sure anyone believes me. But I know what I heard. Has anyone else experienced this? I refer to myself as mama all the time when I talk to her. I refer to her as "mamas baby" ..