Search for contributions made in previous 4 months
You can always search by selecting "Choose Date Range" and entering dates manually (see screenshot below).

If you're looking to use a relative date filter because you need this to be in a report or smart group, then that date filter doesn't currently exist.  

However: I am actively working on making it possible to create your own date filters (CRM-16195)!  I am waiting on someone to review some preliminary cleanup I did a couple of weeks ago.  Once the cleanup is approved, I will submit a change so that custom date filters can be added by an extension.  I already have an extension written that will handle your scenario.

If you absolutely can't wait, and you're comfortable patching CiviCRM, contact me on https://chat.civicrm.org (@junglebird) and I'll give you a patch so you can do this today.