i dont know if i have add but i wanted .. | ADHD Information

hello im 15.in highschool right now... and im having probelms in school like sometimes i just cant concentrate when im reading or when the teacher is talkin my mind just goes some where else .. some times when i try really hard to look at a question or something i just cant my mind will just keep going somewhere else... my grades are kinda bad it all started in 8th grade... i dont know if have add or not i dont know if all this is just something im not sure.. also i remember i was in practice and my mind just went some where else and i didnt even notice next thing i know everyone is yelling at me to pay attention.. ??.. also if i dont have add.. is it possible for me to take adderall?please some one either reply or send me a messege or email me at xcutiemiix@yahoo.com... thank you!