When I make purchases on my phone in iTunes it normally shows up on my iTunes on my computer. Lately I can't find some of my purchases on my computer. What is wrong?
iPhone 4S, iOS 7.0.4
If you mean that they normally download then have you still got automatic downloads turned 'on' on your computer's iTunes : Store tab in Edit > Preferences (iTunes > Preferences on a Mac) - turning it 'on' will only apply to new purchases, if it's currnetly 'off' then you will either need to copy the purchases from your phone or redownload them on on your computer.
Automatic downloads : http://support.apple.com/kb/HT4539
To copy purchases from your phone, connect your phone and do File > Deivces > Transfer Purchases to copy them over, to redownload them use the Purchased link under Quicklinks on the right-hand side of the iTunes store homepage.
Why aren't my iTunes purchases from my phone showing up on my computer
