What Causes Tingling Feeling In Left Arm?

I strained my necked 4 weeks ago and was in extreme pain. The pain went down my left arm causing it to feel heavy, weak and stiff. Only when I relaxed and took ibuprofen did it calm down. I went to my chiropractor who said that because the muscle in my neck was weakened, the muscle above my left shoulder was having to make up for it. In doing so, it was pinching the nerve. He said icing and keeping it warm was all I could do and it could take a couple weeks to heal. I continued taking anti-inflammatory drugs, wore lots of scarves, and relaxed. Eventually the pain in my arm stopped happening 2 weeks later. (My neck is still a little stiff.) However, shortly after I started to get a numb, tingling feeling in my left arm. When I slouch forward in a certain way there's a tingling feeling that goes down my arm to the tip of my thumb. It doesn't hurt. It hasn't got worse, but it hasn't got better. Is this normal? Should I just keep going to my chiropractor. Should I see a doctor? Will there be a permanent effect on my nerves if this keeps happening?