I think you are correct. I've made 88,5$ in February and 145,02$ in March, so I should get 163,4$ this month after taxex. In reality I got 158,34$.
In january I've earned 92,98$ so 7,32$ short of my double March earning, which would be 100,3$. Despite 7,32$ short I've got paid for January 70,31$ (100,3$ - 30% taxes)
Now if I calculate my February and March earning which is 233,52$ (before taxes) minus those 7,32$ I was short for double earnings in January, the sum would be 226,2$. After taking out 30% taxes, the exact sum would be 158,34$ which is exactly the amount, I was paid this month.
So basically, those 7,32$ that they added to my balance in January, the took it away this month.