How old/slow is your CPU? My old GPU manage to mine 4 blocks within 4 days, although 2 of them become stale block.
It's a quad core Xeon E3-1270 V2 @ 3.50GHz. That's why I'm wondering if I did something wrong somewhere.
It's old CPU, but shouldn't be that slow. If you use bitcoind or CLI environment, did you check whether you actually mine block but become stale? Did you follow this guide (which is meant for ASIC) or other one (which use bfgminer)?