Your stub lists the pay period's start and end dates. Common schedules are weekly, biweekly (every two weeks) and semimonthly (the 1st to the 15th, then the 16th to month's end).
Overtime is figured per workweek, not per pay period. On a semimonthly schedule, a workweek can be split across two checks, so overtime from one week may show up on the next check. That is normal as long as it shows up.
Compare the dates on the stub with your own schedule before you check anything else. States set how often you must be paid; see your state page.
Check your own paycheck
Enter your stub and your hours. The checker applies your state's rules and shows anything that is short, with the rule behind it. Nothing you type leaves your browser.