DD is 16 weeks and the past 2 days she has been unlatching and relatching continuously while nursing. She doesn't seem frustrated, and she goes right back on the boob but does it every several seconds. Nursing sessions are lasting shorter as well. Do you think it could be that she isn't that hungry yet? I feed her every 3 hours and was planning to switch to a 4 hour schedule soon anyway. I've also been supplementing with formula more the past 2 days so maybe that's affecting her hunger level too. What do you think this sounds like?