When you upload your photo, it asks for the date taken on. Are you filling in that date? If not, I think it's defaulted to today, so if you're 30 weeks today, it'll go into that week.
Anyone else having trouble with this? I've tried to upload a few pics, and they all seem to go into 30 weeks, which is what I currently am, even if I click a different week first. And then I can't get rid of the ones I've uploaded.