Shoulder pain

[Jwez]

Hey guys i don't know if this question was asked before, but i did my first pin yesterday morning and i still got like a dead pain in my shoulder like some one punched you really hard, how long do you think i gotta deal with it, i've asked someone in my gym and he told me that's commun.
I had the best workout of my life today, felt like a beast and my stamina / strentgh increased. I don't know if it's the juice or just in my head lol how long do you think i'll see great results ( my diet is perfect as well ) Cheers.
I'm a bit afraid of taking arimidex , if i take 0.25 mg it's possible to have an hypersensivity ?