I don’t know what to do

I’ve never gotten tested for adhd. My mom and grandma always make fun of me if I get distracted or play with my fingers. I walk around a lot even when watching or calling someone I walk around the apartment the whole time. The best effort my mom did was when my mom asked if I want to get tested. I said yes just in case. We went to the doctor for my yearly routine. She asks it has come to her concern that I think I have adhd. She asks him. He says has he failed school or gotten bad grades l. Which I did but she proceeded to tell him no and I am a straight a student. I failed three classes. And he said there’s probably nothing wrong with me and let me go. Can I test myself. I’m 16 and want to go by myself.