My LO is 15 wks and over the last couple of days has been crying out or whimpering during her daytime naps. Sometimes it is one quite loud, shrill cry (which is unusual for her as she has a very good temper usually!) or at others a couple of minutes of whimpering. The first couple of times I thought she has woken up, although she never wakes crying, but when I went to her she was still asleep. Is this normal at about this age? Is she dreaming?