Strange "setting" of My Elbow Joint And/or Tendon

Hello,

Brand new to this site, and as such, I was not sure where to post this. It concerns my muscles so I figured this was as good a place as any. Anyway, I've recently begun lifting weights and going to the gym. This is the first time in my life that I've been going on a regular schedule (which may have something to do with this). OK, so, last three weeks at the gym, starting very slow, working only 20 -30 pounds on the arms and slowly increasing the weight (5 or 10 pound increments every subsequent week for the last three weeks). Yesterday, and today, I've noticed a problem in my joint. I'm left-handed, and the problem is in my right arm. At full extension, my arm is fine, a little soreness in the joint, but when I bring my arm up to flex, I feel pressure build up in my joint, or more like something has positioned itself wrong and I can feel it. Anyway, when I fully flex, I feel a shifting, like my tendons are sliding across the elbow joint. Its not dreadfully painful, but it does hurt, and its annoying. I'm worried that I might've overstretched the tendon and that I'm headed for a full tear. I would avoid full flex if I could, but that motion is necessary for my weight lifting (primarily using machines at this point). I was wondering if this is a problem, if I should be concerned... etc. Thanks for your time and attention!

-Eric