For the amount of hashing power that you are putting out that's to be expected. You should probably only be mining if you are using ASIC technology, not GPU's or CPU's. There will be no profitability to mine using the hardware you have. GPU's cost way too much in electricity to see any kind of return and with machines like KnC miners 550+/GHS Jupiters and Coin Terras 2/THS Terra miner IV you will be hard pressed to generate any BTC with the setup you have now.