Yes. I know that feeling. It happens with shoes, too--when you're least expecting it. I wonder how kids' feet can grow so much in one week, you know?
That's why...I'm a huge advocate of planning ahead. Or, buying ahead. Basically, making a list of what your child will need, and then making sure they'll have it, when they need it.
I've never actually done this before, but today I made a list of everything Matthias will need for his next clothing size, which is 9-12 months (yes, he's still wearing 6-9 month clothes... he's a little guy!).
Size: 9-12 months
Play Sweater/sweatshirt (2)
Church Sweater/Vest (2)
Khaki church pants (1)
Black church pants (1)
Play shirts (10-12)
Short/Long-sleeved onesies to wear underneath other shirts (5)
Dress shirts (3-5)
He has a coat, but it's way too big (so we just bundle him up in blankets and a sweatshirt), he has a hat that will fit him till next year, and his socks are size 6-12 months. So those are three categories I don't have to worry about this "size" around!
Now for a few other explanations...
Matthias doesn't normally wear pajamas to bed, except for when it's really cold outside, or when he's had a bath in the evening. Thus, I only wrote down one sleeper.
He doesn't walk yet, so he really only needs one pair of shoes. He can remove his socks, but not his shoes, so I pair the two together for when we're going out in the cold. Win!
Matthias has gotten away with wearing one pair of khaki church pants every single week to church for several months, but in the next size, I figured a little variety might be nice (thus, one khaki, one black).
Jeans. Ah. He wears these every. single. day, and he's an active little man, so they're always getting dirty. He also spits up his food occasionally (yes, still), and so I'll sometimes find myself changing his outfit (or at least part of his outfit) 2-3 times a day. If it's a little bit of dirt, or scrambled egg, I'll wipe it off. But once there's a smell, or potential stain, the outfit is coming off. I like CLEAN.
That's why I wrote down so many play and dress shirts. Basically, that gives us enough room for multiple outfit changes (if necessary), plus not doing laundry every day, plus having a little variety.
Whenever I collect the amount I want in each category, I'll cross it off. For example, I bought one sweatshirt for him at a yard sale (possibly before he was even born), and I just bought another one today off Children's Place clearance (their sales are really amazing). So... that category is complete.
Wow, this is beautiful. I mean, handsome.
So far, I'm loving this method! I can't wait to use it for the girls' spring and summer wardrobes! How do you plan ahead for the next size?
[The clothes pictured are from Children's Place, by the way. Both these items came from the clearance section, though, so there's no guarantee that they'll still be around when you head over there to purchase them... haha. ;-)]