My period is not on shcedule?

Hi. I am 13 now and have been having my period since November of 2009-2010 (not sure which). My period has never been normal I don't think. What's the normal amount of time between periods? Since February 2011, they have happened on:

Feb 20

April 1 (40 days after Feb 20)

May 5 (34 days after)

June 11 (37 days after)

July 11 (30 days)

and I'm not sure but maybe August 14 (possibly 34 days)

Usually they are very heavy with some clots and sometimes I get mild to bad cramps but they are never terribly bad. As for the maybe one on the 14th, the reason I can't tell is I woke up to find some brown-ish spots on my underwear but when I put a pad on nothing ever showed up.

I have not notified my parents about this and when I go to the doctor for a check-up I tell him its normal. Randomly when I'm not on my period one of my ovaries aches for a second then stops. It's always my right one though.

Should I be worried? Please help!

No you really shouldn't worry much right now. It will take a while for your cycle to iron itself out. A normal cycle is between 28 to 30 days. Many women do not have a regulat schedule and they have had their periods for years and years. The cramps and discomfort along with clotting is just another rotten thing that goes along with our periods. Some women skate thru their cycle while others find themselves curled up in a ball with a heating pad on their stomachs, it all depends on their systems. When you feel your ovaries paining, this could be when you ovulate. Again, many women don't even know when the ovulate and they have to depend on a calender if they are trying to conceive. I am NOT saying that is your problem, i am just giving you an example.

You can mention this to your doctor but i think he will probably tell you the same thing. Give yourself some time as you are a newbie to the exciting and wonderful world of "period land" Ugh!