Baby's face, need help?

My babygirl just turned 1 month. Over these past few weeks her face has been getting more & more bumpy. It was very little at first but it seems to be growing more gradually. They are a little red but don't seem to itch or bother her. I thought it was a heat rash as she sweats very easily especially when she sleeps she gets very warm. Or if it was just baby acne. But now I'm not too sure or if it's something I should worry about. It's just on her face, doesn't go below her neck or anywhere else.