jean manufactures are nortorious for making you think you are alot smaller than you really are. or some -- use european measuring, which more accurately measures the HIP ratio.
29 is typically a 6-8 american size. but every manufacture differs. the size 4 is probably put on a size 29 so girls will "BUY" it and "think" they are size 4 -- and they get to think they are smaller than they really are. its just a marketing ploy to play on a girls preception of skinny or small.
that said - you can't go 4 jean sizes UP with water weight retention. if you did, you'd have to go the hospital!
i'd blame it on the jeans, not on water retention. also -- before you start your period you can get bloated -- so your jeans that normally fit you are TIGHT. you won't not fit into them, unless you just recently put them in the dryer and gained some weight :)
I'm sure it's just the jeans! I wear anything from a ladies' 4 to a juniors' 7. I went clothes shopping just yesterday, grabbed two cuts of the same brand; one fit wonderfully, the other I couldn't even get over my bum! I try to avoid buying clothes around that time of the month... I know I'll just feel worse. (Cramps, bloating, AND my favorite clothes don't fit? Ick.)
This will sound unlikely, but it's true for me... (Anyone else with this problem?)
I start to bloat almost an entire week before my period starts. Just a little tiny bit at first, then it slowly builds until I look pregnant. I even stand like a pregnant woman; hands on the small of my back with my belly thrust out... the skin my abdomen gets so tight, I can flick it and get a sound like hitting an uncut gourd! Even my hips, thighs, and ankles bloat! Unfortunately, the bloating doesn't go away until my period is almost completely over. My GYN is treating me for endometriosis with oral contraceptives and an anti-inflammatory, but they're not really doing the trick as far as my symptoms are concerned. I'm going to talk to her about the possibility of checking for fibroids...