Kidney problem or pregnancy syptom?

Okay, so I posted a question about this a few days ago. Ever since last Saturday afternoon (6 days ago) I've been have an annoying, dual pain on my right side. Right in the middle of my side under my ribs. I'm 22 weeks pregnant and this is my first, so I thought this maybe the cause (pressure from the baby). I went tot the hospital 2 days ago and told them what was going on. They took 2 urine samples and said everything came back fine. She said constipation can cause pain in the side/ribs when pregnant.During the night, I must've rolled over on my right side and when I woke up for a bathrooom break, it was sore in that area (in the middle of my right side under my ribs), but when I got back into bed, I layed on my left side with a pillow under my back and it seems to be getting better. I never get this dual pain anywhere on my left side. What is this? Is is kidney problems or just the weight of the baby?