I have started menstruating and it has only been real blood once, all the other times it brown or dark brown for months. They are always light and last two days! (btw I'm 12 so... ) and I would get bloaty and fart a lot before my period then after the two days the period and pms stops. But this month the pms has been going on for days I keep farting and having lots of poop.. lol seriously and sometimes my chest would get a burning sensation when I touch it or breath. (Left and right) by the way breasts are developing. Please help I'm scared..

I think the things you are describing are normal for a person who have just started their Periods and are new in the cycle. Your body is adjusting and Its going to be normal after few months. The cycle can go to 3 days to 9 days. Not sure about the burning sensation in chest but everything else looks normal. But f you feel the chest burning is getting strong please see the doctor.

No need to be scared (although I was at 12 too, because I didn't know ANYTHING)!

Brush off your google and start reading for hours and days. There is so much to know, from what brown blood means (older and exposed to air) to charts showing the huge hormone fluctuations that affect water retention, mood, digestion, and as far as I'm concerned, absolutely everything under the sun. No, it's no fun, but you can learn ways to cut down on a lot of the annoying aspects, and joke about it with friends.

Talk to your mother, if you still have her and live with her. You may have inherited a few things from her, and besides, she has been through it all, and should like to have you ask her. And she needs to help you with what you eat.

Since you are having lots of farts, you could also be having stomach gas too (same gas), and what we call heartburn. Try a Tums. It should work instantly to make you burp.
You could need a trip to a clinic if the chest pain isn't gas. Swollen breasts can hurt too though, so work on all this a bit first.
As for digestion, you are probably a girl who is sensitive to many foods during all these hormone changes each month. No fatty foods, no carbonated sodas, no spices, no processed meats like pepperoni, and maybe even no spaghetti sauce or any tomato sauce! Rough, I know. But try it.

As for pooping a lot, I'd say you are lucky, because for many, it's the other way around, and constipation is very uncomfortable.