if you have had sex then you could be pregnant. which might be the case for it being late. you could have missed timed this one so you think you are late. i would check to see if you are pregnant as to me this is a more likely cause but you did say you knew when they where due to come.
I have been having my period for 27 years. For the first 10 years or so, I was lucky to get a cycle every 40 to 50 or more days (should be 28).
I didn't have regular periods until after I had children. It's not that unusual for the first couple of years to have irregular periods.
Sometimes missed periods or an irregular cycle can be caused from too much physical activity and/or poor health/stress/Fatigue. Irregular or missed periods can also denote anemia.
Go to your gyno and find out. It's the only way
For 10 bucks at a drug store get a take home pregnancy test. If not pregnant and it continues to happen your GYN may suggest putting you on THE PILL to regulate you.
