Baby gasping for air

Hi I was wonderingif anyone has experienced this with their baby. My love is 3 months old and she will gasp for air. It's like she is trying to catch her breath. She has done it a couple of times last in the last month or so but last night it was a long gasp followed by coffing. It freaks me the hell out! I'm planningon taking her to the doctors on Monday. But I was wondering if this is just something baby's do.