Baby burrowing head in chest

Gibbeanski
Recently, after I feed my LO (just over five weeks old) and put her up on my chest/shoulder to burp her, she will put her face facedown onto my chest/shoulder and she will kind of burrow her face (wiggle her face back and forth) on me. I try to get her to settle her head so she's laying on the side of her head/face, but she insists on being face down on me. Since she won't stop doing that, I always have to take her off my chest in that upright, burping position and just hold her in my arms cradle style, which I don't want to really do because she has reflux and I want to keep her as vertical as possible (I always end up inclining her in that cradle position but it's really awkward). 
Has anyone dealt with this burrowing before and if so, what could this possible mean? She never really did this before this week.
TIA!