hi guys please help me ive got 28hm/s but no shares. WHY???

ETH - Total Speed: 28.162 Mh/s, Total Shares: 0, Rejected: 0, Time: 00:00
ETH: GPU0 28.162 Mh/s
ETH: 06/20/17-11:11:16 - New job from eth-eu2.nanopool.org:9999
ETH - Total Speed: 28.163 Mh/s, Total Shares: 0, Rejected: 0, Time: 00:00
ETH: GPU0 28.163 Mh/s
ETH: 06/20/17-11:11:22 - New job from eth-eu2.nanopool.org:9999
ETH - Total Speed: 28.162 Mh/s, Total Shares: 0, Rejected: 0, Time: 00:00
ETH: GPU0 28.162 Mh/s
GPU0 t=55C fan=0%
ETH: 06/20/17-11:12:04 - New job from eth-eu2.nanopool.org:9999
ETH - Total Speed: 28.162 Mh/s, Total Shares: 0, Rejected: 0, Time: 00:01
ETH: GPU0 28.162 Mh/s
ETH: 06/20/17-11:12:07 - New job from eth-eu2.nanopool.org:9999
ETH - Total Speed: 28.162 Mh/s, Total Shares: 0, Rejected: 0, Time: 00:01
ETH: GPU0 28.162 Mh/s