I have 6-7 day periods?

They may be on the pill as well which will shorten their periods.

It's normal I get mine totally different. 4 days or 5 or 6 or 7 or even 9 it could be they are more active and use tampons. I'm usually active so my period last 4 days:) and drink a lot of water! It helps.

I'm skinny and it lasts a week for me too...

I had a two week period my last cycle!!! :(

That sucks for you, I only bleed 1 1/2 - 2 days. It differes on the person.

Totally normal. I'm a big girl and I used to have periods that lasted about a week. Now it's down to 5 or 6 days. Don't worry about it. Everybody is different, just be sure to get those thick pads so you won't bleed through. I was in school once, sat down really fast, and I felt a little blood seep out of my pants. Good thing it was the end of the day...

ditto

Yes it's normal I get that too.

Yes it's normal. Women bleed different amounts. Some more and some less.

stress can effect it too. i have seperated from my baby's dad and i stressed so much that i didn't get my period for 2 whole months!
i thought i was pregnant with a second baby(from my x) but luckily it was just stress. because i got my period the end of that 2cd month.
if you are truly concerned go see a doctor.

If anything it is your friends who are abnormal. I heard that it has to last at least 4 days to be a period..

It's not necessarily abnormal but it can be an indication of a problem...things like fibroids may cause longer periods. You may just want to get a check up.

I bleed 7 days too so don't feel bad

Weight can effect the duration and heaviness of your flow

I think it's normal cause I'm the same way :)

Look online it can last like 8-9 days. (like mine :( 8 days) it should be 4-9 days to be a real period. That's why birth control pills give 7 days for the blue pill.