Depends on what your hash rate is.
However, if your miners went off you would have seen the ~31hr ramp down of payments, then when switch back on the ~31hr ramp back up.
Your per block reward depends on your hash rate vs the pool hash rate which goes up and down all the time.

If the pool hash rate goes up, we expect on average to find more blocks so if all blocks were 100%, you'd average less per block but more blocks.
The reverse of course is also true if it went down.
The Pool->Graph menu shows you the randomness of the pool hash rate