I don't work for Tesco, but if you have contracted hours, your pay for those hours will be listed as something like "contractual pay". If you've done overtime that should be listed separately, and will be paid but normally at the same rate as your contractual hours until you get up to a certain number of hours, usually 37.5 or 39. However, you need to check the cut-off date for payroll - the date which your manager has to enter your hours by in order for you to be payed for them that month. For example, if you did 4 hours of overtime on March 10th and the cut-off date is March 15th, you'll get paid for them at the end of March, but if you did overtime on March 17th, you'll get paid for it at the end of April.