Does cpuminer do its work?
You are mining, but most pools today have a minimum share difficulty requirement, otherwise very fast miners bombard them with shares that they have to process and discard. For many pools this is at a minimum of 128 or higher, meaning it would take several days for a CPU miner to find a share on average. No pool has a payout of any less than 0.00001 BTC, so there is absolutely no chance of you ever being paid for your work if you are mining using a CPU or GPU at this point in time.