3 Periods in the Same Month?

Starting your period is like menopause in reverse.
It's going to take awhile for a regular cycle to establish itself.
Several years in fact.
Don't expect regularity before 16 yrs old.
Measuring your weight in kg tells me you are likely not in the Usa.

What should you do?
Talk to your mom if you have concerns.
Perhaps your school nurse can talk to you.
Decide on sanitary pads vs tampons.
Maybe get a heating pad in case you start getting cramps.
Relax!
You will be dealing with this for the next 40 or so years of your life.

These are not all true periods. These are normal (for your age) bleeding episodes from hormones struggling to work. A kid new to the basketball team doesn't always make the shot or the pass - a body new to progesterone and estrogen doesn't always get everything working without a lot of practice time. And the body is not a precision machine anyway. Some women never get regular periods, which is frustrating. But very few teens are totally regular. (And although you didn't ask, let me add that this is why it's practically impossible to avoid pregnancy by just using a calendar as birth control - so when your time comes to be sexual, I hope you will remember to take care of contraception first.)

Your best resources are a caring parent or aunt, the school nurse and your own doctor. You can call your doctor on your own too - leave a message and a good time/number to reach you. Start practicing speaking to your medical professional on your own if you can, even if you can't do the whole thing or take the whole matter into your own hands. With practice, you will get better at it and feel less self-conscious. But you've done a great job here in listing your dates and your symptoms. Start keeping records of these things so you can always report to your doctor if something seems off to you! Lots of adult women don't do that, and i makes it harder. So you are off to a good start!

The best thing to do is to get a checkup, but spotting and delays in your period when you first start getting it is normal, also an excess of exercise, stress, low body weight or increased body weight can have an impact as to whether you have a heavier, lighter, less frequent or more frequent period. I had a co-worker who weighed about 85 lbs. and she would get her period maybe once every 3 months, and it'd last just a few days, she was anemic too. I was worried for her once she told me, but she said she had always been that way and it was because of her low body weight.

At your age, periods can be wacky and unpredictable. Also, you are fairly light in weight, which can also make a difference if you have low body fat. However, the thing you must do is talk to your mother. She can help you get to a proper doctor. If your mother is not around, then talk to your father. Trust me, it may be embarrassing for you, but it is something parents expect to do. If you cannot do this, please talk to your school nurse and ask for help. If that fails, maybe you have an aunt to talk to? No one here is able to diagnose you and your unique body, but we are here to give you advice if you need it.