That depends on what you mean by "held back".
There is a very legitimate, very legal method of paying employees called "paying in arrears". To give you an example, suppose the pay period runs from Sunday to Saturday, and payday is Friday. Pay is weekly in our hypothetical example and you work Monday through Friday. Under the paying in arrears method, a new pay period begins tomorrow, Sunday January 11, and ends a week from today, Saturday January 17. You start a new job at this company on Monday the 12th. You work Monday through Friday. But when the paychecks are handed out on Friday the 16th, you don't get one. That is because under the "arrears" method, the checks that are handed out on the 16th are for hours that were worked between the 4th and the 10th, not the 11th through the 17th. When the paychecks are handed out on the 23rd, THAT's when you (and everyone else) gets paid for the 12th through the 16th.
As I said, this is a very legal and very legitimate way of handling pay. It makes far more sense, in my opinion, than paying on the 16th for hours worked on the 11th through the 17th. For one thing, you haven't even worked all the hours yet when you get the paycheck; what if you work overtime on Friday? So the "arrears" method is much more accurate.
But for some reason, a great many people persist in thinking of this method as "pay being held back".
We do not have any way of knowing what your employer's pay practices are. But if they are paying by the arrears method, that is legal and it does NOT constitute "holding back pay".