Has anyone experienced back pain yet? I'm only 15 weeks, 3 days and in relatively good shape. I haven't been working out regularly but have done prenatal yoga a few times. I keep experiencing left sided-mid back pain, especially when I turn or lean. It's not sciatica pain, because I've had that before. I haven't gained more than 4 pounds yet, so I feel like it's way too early for this...! Anyone experience anything similar??