Hi I Am Going In Holiday At The Beginning Of

Hi I am going in holiday at the beginning of june and then again the beginning of July. On both occasions my period is due within aday or two of going away. I have used tablets before to postpone my period but after taking them for over a week to two weeks I experienced spotting. I was thinking of taking some for two weeks at the beginning of June so that my period would start before my holiday at the beginning of July. If I do this will my next period be 28/29 days later or could it mess up my cycle meaning I may have a period whilst away from two weeks at the beginning of July. The tablets previous prescribed were norethisterone (Utovlan)
Thanks