Aw mama, 4 days is quite a while talaga, mas better kung consult mo na ang pedia or midwife mo para ma-check kung okay lang ang baby mo, kasi kung purely breastfed siya, dapat may bowel movement every few days at least. A few of my mum friends had this worry din and their doctors just wanted to make sure baby is gaining weight at wetting enough diapers (that's the main sign baby's getting enough milk). Don't stress too much pero better safe than sorry with these things, you know?