The reason you haven't seen a payout is because most pools have a threshold level below which they won't bother sending xmr to you.
Your share per tick is: 160 H/s / 50.53e^6 H/s, with a network rate of 50 megahash per sec, right now. The previous mining reward was 9.2481 and a tick happens every 2 minutes.
With a threshold of 0.1 XMR we get:
0.1 XMR / [(160 H/s / 50.53e^6 H/s) * 9.2 XMR / tick * 0.5 tick / min] / 1440 min / day = 4.77 days
In other words, if the pool has a threshold of 0.1 XMR before paying out you can expect to mine for almost two days without seeing any returns. On top of that comes any variance. Some small pools might not find a block the day you're due for a reward, which would cause an additional day in delays.
Follow up answer: No, you can interrupt, and come back to it later. Your balance shows the amount already won. Every time your balance changes, it's your fair share of the block reward, which the pool holds for you until you cross the payout treshold.
However, note that interruptions affect how much you will win in the first place. There are 2 different pool policies PPS (pay per share) and PPLNS (pay per last N shares).
With PPS, you will always win a piece of block reward proportional to your shares submitted to the pool / total shares submitted to the pool. With PPLNS it's a bit different, to discourage pool hopping.