cynn04, no idea about that. maybe chicken essence will help to boost your strength. if you are open about TCM, can go to one that specifically treats pregnancy-related issues to see what doctor has to say? or it could be a sign that you need to do some simple exercises to strengthen the muscles there.
nazriah, I have the same issue as you in the butt cheek department... mine is predominantly on the left side. when I sneeze, the ache will come from lower back to butt cheek to upper thighs. must hold the butt area when that happens. so unglam. lol!
missyblueberry, can give ginger cream a try for topical relief of backaches. if the pain is really bad, then it probably won't be effective.. I bought my ginger cream from here, in case you are keen to try out:
http://originsjamumassage.com/shop/gingerly-yours/