For the last week or so, my baby has been trying to suck her thumb WHILE breastfeeding! Is there a reason for this? I wouldn't mind except sometimes she pinches or it just feels uncomfortable. I have tried taking her thumb out of her mouth, or taking her off the boob but she fusses and tries to put it back. It seems to mostly happen when she's sleepy. Has anyone heard of this before, or any ideas on how to deal with it? Thanks!