Its common.. I had sciatica my whole first trimester but haven't had much of a problem since I'm in the second trimester.
My pelvis is tilted back and now that I am half way threw my pregnancy and the baby is rapidly growing I have pinched nerves. I go to the chiropractors office and use the heating pad often for pain relief.
Very common I have them all the time try back Massage , heating pad or warm/hot shower might help u just be careful not to get it to hot it might make u feel bad if u do.