Sparks--This does sound a bit like sciatica but it could be a pinched nerve also. Would your doc allow you to see an accupuncturist? They are supposed to be a godsend for so many people. Personally have never tried one but friends that do see one swear by them.
You actually sound pretty funny with this pregnancy, stop worrying and relax. I have a feeling your heart palpitations are anxiety attacks brought on by some stress. Relax and pamper yourself, this is the time for it. Good luck with the rest of your pregnancy.