Go see your doctor. One testicle is supposed to hang lower than the other, and you might just be seeing the result of the trauma that it seems more noticeable to you than before, and there are tubes and blood vessels in the area and all of that is normal. But probably the area is bruised and traumatized, and it NEVER hurts to see a doctor when you have had physical trauma.
Here is from another website:
Your urologist can often figure out how bad the injury to the testicle is with a physical exam. After asking questions about how the injury occurred, as well as other questions about your health, he/she will look at your scrotum. It's often easy for your urologist to feel the tough testicle cover, as well as the thin, soft epididymis. He/she will also feel the structures that run into the testicle--the artery, vein and vas deferens--to make sure they're normal.
If all seem normal with no injury, your urologist will likely give you pain meds, such as acetaminophen or ibuprofen. You'll also be told to wear a jock strap to support the scrotum.