SI joint pain

Karen
Anyone else experiencing SI joint pain??  I thought at first that it was sciatica but I only feel it just above my left butt cheek, where the SI joint is.  Anyone have any suggestions for remedies??  I'm a very active person--in the gym and/or walking 4-5 days a week and I have a very active job.  It doesn't ache or anything but I'll get a sudden twinge every once in a while that takes my breath away!