I have been having chest pain in the left chest with pain in my left arm and shoulder as well. It lasts 5-7 minutes and will go away when I sit down or lay down. It occurs mostly later in the day and after I have been walking or doing some other activity. Is this a heart attack or something else. In the mornings I am totally fine.

This is not askanurse.com.
Of course any pain on the left side of the chest/left arm is a possible sign of a heart attack. Of course we can't know if it is or not, online. The sooner you are checked out the better, regardless of how you are feeling at the moment.