wasn't sure about
Creí que no estaba segura de lo que decía.
I thought she wasn't sure what she was saying.
No estaba segura de qué estaría pensando.
I wasn't sure what he might be thinking.
No estaba segura de adónde me llevaba todo eso, aparte de hacer feliz a Antonio.
I wasn’t sure where all of this was leading, other than making Antonio happy.