yep - honestly, an S7 will only make you around $100 a month right now, at the current difficulty. With the increasing network difficulties, it won't break $80 in the next month or two.
..........
You probably mining in the wrong place.
0.0144 BTC /day = 0.432 BTC/ last month - Antpool ( nicehash = 0.01536 BTC /day 0.46 BTC/last month from one S7 4.8 THs )
It is 186 USD not around $100 a month.