help--having chest strain/pain

Hi all--I'm new...I increased weights during my arm workout two days ago, and then the day after, I had a great long run. Probably longer than I normally do, but I felt great during it. Well, yesterday and today, my chest muscles feel very strained. Like a twitching in my chest wall area, if that makes sense. My husband thinks it's due to the increased weights, and then pushing myself...maybe without warming up enough? I dunno, but it totally stinks to be dealing with this, because it's so tight on the left side of my chest, like into my collar bone, even. Could it be from that? And, I'm currently taking ibuprofen for pain--but should I be icing it? I tried to power walk today...to keep up with my workouts, but I walked up this huge hill, and I had to walk home. As I took deeper breaths, the pain and twitching in the muscle came back. I'm used to leg pain, but chest (wall) pain is....uck...horrible, too.

Any advice? Thanks!