You don't start over, see it as a lotto game.
You have 10 dice in your hand and throw them again and again up, until all land on the 1.
The odds are everytime the same, there is no progress on to finding a block.
with 2,7 Gh @ 877226.666667 difficulty you will need to find a block:
Average 16 days, 3 hours, 37 minutes
50% 11 days, 4 hours, 40 minutes
95% 48 days, 9 hours, 13 minuteshttp://www.alloscomp.com/bitcoin/old_calculator.php
Odds are not so high to get one in this difficulty, and in the next the odds go down.