Kind of worried

My baby is 2 1/2 months lately I notice when she’s waking up she rocks her head back and fourth I don’t know if she’s just trying to wake herself up and force herself to wake up but she usually just goes back to sleep. Is this normal ? I don’t know why it’s not allowing me to send a video but it literally is just her laying down eyes closed shaking her head back and fourth like saying no and then she stops and goes back to sleep. Ok thnx bye