The first injection I EVER did was 500mg of Omnadren right into my ass. HOLY FUCK!! I couldn't walk, put on underwear, drive my car, go to work....etc. I was useless for over a week. But the good news is any injection I did after that never really hurt all that much. There has only been a slight soreness even with shots upwards of 3cc!
Your fine bro, don't worry cause it is normal...I don't know if what I went through was normal but I'm still alive today so its all good!