Swelling in my arms... do I need to go to the Dr?

I tried Googling my issue but to no avail, so here we go reddit. On the 19th I started a 'Boot Camp' type class and started working out to help boost my weight loss. On the 24th I noticed that my arms weren't just 'sore' anymore from the work out but actually painful. I laughed with another girl in the class because it looked like I was turning into Popeye. Then... later that evening I went out with friends and after a few rounds of 21 I was Popeye. My forearms were incredibly swollen and painful. Went home and went to bed after massaging them for some time. The next morning the swelling had gone down.

I decided to take a few days off and today went for a four mile walk. At the end of the walk I just now noticed that my arms were again swollen. Not as bad as before but just beginning to swell up. I sat on the couch with my arms above my head for 20 minutes and it seems to have gone down already but I'm worried... it's weird.

I don't have insurance but if this could possibly be life threatening then I certainly will go... I just don't know at what point swelling in the arms becomes something I need to see a professional about. :/

edit: Just so people know, I only posted this because I was already considering going to the Dr... I just really don't want to.