I'm 4 months pregnant my left side of my back hurts close to my butt cheek i can't walk or bend down i can't do nothing ?

Please call your OB: U need evaluation, you may have sciatica and can be referred for physical therapy and evaluation by an orthopedic doc or you could have other causessomething else.

Sciatica: This definitely sounds like sciatica based on the distribution of pain that you are describing. There are many treatments for this in pregnancy including: chiropractor, acupuncture, massage, warm compresses, prenatal yoga and stretching exercises. Good luck.