Lower back pain-right side

Ok I've been having back pain for the past 3 days. It feels like my bones hurt or a muscle or disc is messed up. My estimated due date is Feb 2nd. All my bloodwork is fine, had my 1st U/S today and everything looks good (not far along enough to see the actually baby yet, but saw the sac etc, and I've had no spotting or bleeding. My doc isn't concerned with it having anything to do with the pregnancy because it's so low. I recently had a UTI so I was concerned with it being a kidney infection, but he said that pain would be higher. My back is killing me mainly on the right side and down into my butt. Should I just wait it out or go to the immediate care?