What does a peck kiss mean?

I recently started talking to this girl, we have been on many dates together and when we are together we snuggle and hold each others hand about two nights ago she text me and said she wishes I was with her in bed still, and that she wanted to kiss me.i asked her why didn't she and she said she never makes the first move. last night I took her to a movie and when I said goodbye I went in for the kiss but only got a quick peck. she constantly tells me how much she likes me and that I make her happy. should I be worried ?
What does a peck kiss mean?
Post Opinion