My daughter is 13.5 weeks old, just over 3 months. She was sleeping quite well for a time, going down around 10pm, waking around 3 or 4am, then back down until 7 or 8. Now, she wakes up every couple of hours and is frantically searching for her hands/thumb to suck on. She is so obsessed I think it wakes her and keeps her from falling back asleep. Previously I could rock her back to sleep but now she will only settle again with a feeding. This has been going on for a few weeks now. She also just learned she can kick her legs up to roll onto her side a week or two ago. Is this sleep regression or does it have to do with her search for her thumb? Any tips would be great!