Because you are so young you can expect your periods to be a little unusual. How long have you been getting your period? If you've been getting if for several years, then this may be a bit unusual. Also, what is the bleeding like? Is it like a normal period? If you are not bleeding heavily or passing clots bigger than a quarter or don't have any cramping, then chances are you are ok. Sometimes we just have a wacky cycle. I am 31 and recetly started getting spotting before my period. No one has a good answer as to why it's happening, so I guess my cycle has just changed. Wait a few more days and if it doesn't stop then you need to call a DR.
I first started getting periods when I was 14. Is this the same for you? They can be highly irregular when you first start. I started one month, and then didn't start again until 6 months later, then 3 months later after that one. The doc put my on bcp to regulate my period. If it is heavy flow for 13 days, you need to see a doc. You could be losing too much blood. If it's just a little discharge, I would wait and see what it does next. HTH
sweetie I wouldnt worry I used to get my period at your age any where from 7 to 15 days at a time and my doctor suggested birth control pills saying that this would regulate my period. Maybe you should sit down with your mom and talk to her about your worries and suggest a visit to your gynocologist. Good luck I am sure you are fine.