2 periods in one month

I'm 20yrs old and have been having a lot of unprotected sex with my BF using the pull out method for birth control. I had a period on sept 8-15 (7days) then a week later on the 20th I started ANOTHER period but it's a heavier flow than is normal for me. I've read a lot of women have 2 periods in one month when they discover they are pregnant. Did my period come 2 weeks early or is something wrong?

[Raevicious]

Generally if you get your period, you're not pregnant. The pull out method IS NOT a form of birth control...

[stacey10]

definately not a good form of birth control

[samiba91]

A period generally means your not pregnant.

[mommyof3n1angel]

I have been using the pull out method for 3 months without getting pregnant this is my first month trying good luck

[kimisup]

You could have had a miscarriage women can have a period up to four months after they are pregnant....