Arms , shoulders and upper body hurting after going to the gym?

I'm 19 years old and I rejoined gym a few days ago after a gap of 7 months. I follow the same routine as I used to 7 months ago...did't change anything, same work out style. After I came back from gym in the morning, it did not hurt that much, but while I slept at night, it was hurting real bad. It hurts even more than what I experienced when i joined the gym for the first time in my life. What should I do? is it normal?