Sorry to hear that you have bright red blood that comes out on the toilet paper after you stool and that you are worried about what might be going on. I will give you my thoughts as to what might be going on, but ultimately I am going to recommend that you make an appointment with your primary care physician
to get an exam which will help a lot in figuring out what exactly the issue is. There are a number of different reasons for bright red blood from the rectum. Without being able to ask you questions, it is hard to narrow down what might be going on specifically in your case. For instance, anal fissures (dry cracks in your anus) can bleed during and after stooling which will give bright red blood. This typically will cause pain, and in particular when stooling. Also hemorrhoids
(dilated veins in the rectum/anus) can cause bleeding
, and can even prolapse out of the anus. These also can thrombose (or clot off) which can be quite painful at times. Lastly as a young female, there can be menstrual issues that can manifest themselves as bleeding when stooling. Your general practitioner will be able to examine you, and if there isn't something obviously wrong with your rectum, then they may want to be a pelvic exam to make sure there are no abnormalities. If they find something, they will be able to refer you on to the appropriate specialist.