Is my current employer cheating me out of pay?

I work at Open Pantry, an I've been working there for two months now as a sale associate making 8 dollars an hour, my hours are 7.5 and I work 3 days out the week, for this week I picked up two extra days, Saturday and sunday, 7.5hours for Saturday and 9 for Sunday,giving me 40 hours total, I get paid every Wednesday, and my checks gets deposited around 1:42am every Wednesday, when I got my deposed it was only 180 dollars, and I'm wondering if I've been cheated, I live in the state of Wisconsin and idk how the taxes here work, so if any one knows can you please explain! Thank you