It does sound like your sciatic nerve. I went to acupuncture to induce labor and it worked great. I've also heard it's good for other aspects of pregnancy so maybe as above it could help you.
I had a completely numb left leg and sharp nerve pain in my back, so I went to an acupuncturist who specialises in pregnancy. I've had two treatments and feel 100% better. Treatments are kind of yucky feeling but they last an hour and my legs feels (relatively) normal again!
Not sure if its normal, but it sure sounds like your sciatic nerve. Hope you get relief soon