Question: I have pain in the inside of my elbow, just below the biceps and to the inside. The painful "thing" is like a "string" that raises up when the arm is flexed. I attach two photos with an arrow pointing at it. I can feel the pain even with a very gentle move (just holding the arm at 90º is enough). It's as if that "string" were overstretched, it feels very strained, and it is as if a minimum effort was able to pull it very strongly. I can extend the elbow with no pain, however.
I started feeling this pain (but in a very mild way) 6-7 weeks ago doing biceps curls (very light weight, and no more weight than usual). I stopped and have not gone to the gym since (I have coccygodinia and no longer attend the gym) but the pain continued with domestic chores etc and this morning it has come to this point when just holding the arm flexed with a dish causes mild pain in that string (maybe I slept in a bad position or have made some effort?). The pain grows stronger if I make a bigger effort but I dont dare to try too much.
I would like to go to my GP but since today is saturday I won't be able to see him until tuesday if I am lucky.
Can you tell me what it is that is wrong with my arm and what should I do in the meanwhile? Thank you.

Thank you for answer. I have been looking at the "tenis elbow" in the internet, but it seems a little to the side of where I have the pain (here they mark the spot with an "X" http://emedicine.medscape.com/article/327860-overview). My pain, marked as "string" in my photos is a little bit upwards of the "x", very close to the elbow hollow. Is it still tennis elbow? Thank you.