Gagging?

Nina

My one month old keeps doing this thing where she can't breathe. Either she is gagging on excess spit or holding her breath, I can't tell. But she arches, her eyes get big, she turns blue with her mouth open likes she's going to cry but no sound comes out. Her nose is clear, so she can breathe out of it, but she doesn't! Has anyone ever experienced this? She's done it 6 times now and we have a doc appointment Monday. My reaction is to pat her back and suction her mouth out, and it's terrifying. Please help!