What does it look like at the pool?
From your screenshot, NemosMiner has been running for only 22 minutes. Your trust level must be around 6%.
If you just earned some blocks in these 22 minutes, the Earnings Tracker will assume constant earnings and extend to a day.
Just wait for it to learn and get a meaningfull sample to do the projections. That is what Trus Level indicates.
As to negative values, same thing, how does it look at the pool?
Pools are updating estimations sometimes lower than when you earned the block resulting in lowering your total earned.
I such cases, you're actually having negative growth at the pool.
Edit: The sample frequency for Earnings Tracker is 10 minutes which sometimes causes discrepencies between different instances. This will be change to 3 minutes in next version of NPlusMiner to avoid that.
Edit 2: One example of cases where we might show negative values (accurately) :
https://github.com/nemosminer/NemosMiner/issues/542