Baby's vagina turned bluish

So my little girl is one month and today she had some bad gas and became really fussy. At one point I was beginning to change her and she began fussing so bad I was worried about her breathing as she was fussing so bad her face turned red and she seemed to almost hold her breath then as I tried to change her I noticed her vagina was bluish in color.  My husband and I calmed her down and when we checked again it was back to a normal color. I am going to call pedi in morning just to check but has this happened to anyone before?