You don't give enough info for a good answer, and womens cycles can be 'off' for so many benign reasons. If you have been having UNprotected sex you might see either your PMD or GYN and let her/him do a blood preg test and go from there.
Hi there. Well, are you having unprotected sex? If you do not wish to be pregnant, then make sure you are using reliable birth control. That is important! After that, there are other reasons why cycles can be messed up and periods will be late. A woman can have an 'off' cycle or two for no reason at all. Or stress, depression or anxiety can cause a period to be late. Hormones can be off balance. The thyroid can be slow. Weight gain or loss can have an effect. Any of those things going on??