So far this boy has a lot of Gap, Carters and Joe Fresh. Gap is my fave and what I've been buying mostly.

I'm wondering how Gap fits versus the other brands? Gap sizing is different (0-3 month), where Carters is just newborn then, 3 months, then 6 months, etc.

He is due in March and I want to get this cute summer one piece that is on sale at gap, but I'm wondering if he will be out of it 0-3 at 3 months (june)? Since it won't be warm enough here to wear before that most likely. Or does it run large? I know it totally depends on how big he is, but just wondering in general if Gap runs large or small or right on track in your experiences.

TIA!!