My Left Epididymis Is Bigger Than My Right One ,

My left epididymis is bigger than my right one , and swollen after a day of simple laying in bed. It was painful to touch my testical or walk around. I eventually went to sleep and the pain went away, but the left epididymis still seemed big. Is this normal after a sudden period of pain. I've read some articles where it says it may be caused my an infection. Is this normal to have one epididymis bigger than the other one, after a brief period of pain?