When you say that now your period is "always a few days late," does that mean your first month was 28 days long, then your next month was 32 days long, and then your next month was 36 days long? Or do you mean you used to have a regular length of menstrual month (such as, 28 days from period to period) and now you've shifted to a longer menstrual month (such as, 32 days from period to period)? If your cycle has shifted and is a little longer, but is regular at that new number of days, I wouldn't worry at all. If it's getting longer and longer every month, that is more unusual.