I don't know whats going on :S

Hi i am a high school student who has been having weird bowel movements and they are on and off. First it was constipation then it was fine. Then it was diarrhea for a week but then again went back to normal stools and bowel movements. Now its been 2 months or so and sometimes my poo is fine and sometimes not. One day at school i have sharp pains in my lower abdomen and the other i don't. I see this weird pink fluffy stuff in my stools now and also lately i have been having short, slim poop and not a lot of it. Should i just go see a doctor? Because honestly i feel like normal i just been having these weird bowel movements.