My dd has been very fussy for the past few days while breastfeeding. She is biting me and pulling off a lot. She is even fussy when not eating. She tries to chew on everything she can get her hands on...but when she gets it in her mouth, she nibbles on it a couple of times and starts to cry. I don't see any teeth coming in and her gums don't look red or anything. Could she be teething or could it be something else?