Newborns

My daughter is 2 weeks old ive fed her changed her now trying to rock her to sleep she will act like shes going to sleep then a few mins later just start crying out of no where just for a few seconds then she will take her pace and hush she did the same thing last night but while shes crying she will reach for my hair and pull it like shes in pain or something. Could she just be fighting sleep or is there something bothering her?