Could Delayed Menstruation Be Due To Laparoscopic Treatment?

Dear sir i want to ask the question about my wife.she normally get minstration on 4 of the month.last month she got the treatment of laproscopy on the date of 23,now its 18 of the month and she didn t got minstration.i want to know the reason that why the periods are delayed. ... thank you Tanzeel ur rehman Thank you