I've recently come back from a holiday to Greece with my husband we were there for 10 days and are from England so the time difference is only two hours. I had a period last month and was due my period four days ago , I've taken countless pregnancy tests and know that I am not pregnant, so I was wondering if the time difference can effect my period for this month? Sounds silly but I only ask as a friend of mine went backpacking in south east Asia for 2 months and never had a single period though her periods were like clockwork back in the U.K. .