Period is acting funny...but normal...under NO stress..need more answers?

I'm 2 days late without being sexually active. I thought it was interesting really, while in school my period was on the dot or maybe a day or two earlier, but ive never experienced a late period after 2 years of having it except for once or twice. Well since school has been out (jun 5)...ive been changing my sleep schedule ALOT. First i was sleeping during the day and up at night, then i went to sleep at 5 pm and woke up at 4 in the morning and just stay up. Now im staying up all night until about 6 AM and sleep till 2 PM...its weird and worse because i dont have a job. Well yeah and i also just started working out for the 1st time in about a month these last 4 days.
ALSO--my PMS is strong this time around. I'm having more pre-cramping...not worse, just more of it. And my breasts are veryyy tender. Usually all my pms stops completely the day of my period. I still have PMS though

actually i had a period for 5 years in novmeber...i got it when i was 13 and now im going to be 18

You may not think or feel stressed out but your body is. If you go to the gyno thats exactly what they are going to tell you. If you are having even a slight indication PMS symptoms then you period is soon to follow

Well, all of the variations in your period are totally normal. Menstrual cycles happen over a range of days, say from about 2 weeks to more than a month, depending on the woman. They're also REALLY easy to alter.

Everything you described, as far as all the wacky changes in your schedule, and ESPECIALLY starting to work out, can completely skew your period, and the amount of cramping, and the amount of bleeding, even how many days of bleeding, you may have. It's kind of interesting that this particular function of the body is so easily altered.

The exercise especially is well known to change or even stop periods. Most young women who are athletes say in the Olympics (some of those girls are very, very young, like 15 and 14 or even way less) stop menstruating altogether as long as they are training and competing.

Also, as you get older, you will occasionally notice changes in your periods: how much, how frequently, and how much cramping or other PMS symptoms you may have. Again, this can switch around really easily. Say you have your period just the same until you're 25, and then you diet and lose that 20 pounds you have been meaning to: your period may be skewed by that too. Too much caffeine, sugar, not enough calories, and so on, can all alter it.

The increase in the PMS and breast tenderness and cramping is probably just a normal change based on your getting a little older. You've been having your period for a couple of years, so probably it's settled way down into whatever your body considers to be normal and necessary. You'll probably notice changes like that from time to time in your life, all the way up until Aunt Flo packs her bags and leaves town.

The body's weird that way.