Hi, I m 28 years old, I ve been married for 18 month. My husband and I was doing the pull out method until 4 months back when we are trying to conceive. I have always had a 28 day cycle on the dot. However, ever since we were trying, my cycles have become early or late. Last month was 4 days early and this month it 3 days late. Is semen causing my period to be irregular or there is some other reason causing my period to become irregular?