it could be! i know it was for me! my first pregnancy early i developed horrible horrible pain in my lower back which can be mistaken for sciatica but i'm pretty sure it was my si joint. with my second one week after conception (pre pregnancy test) i started feeling my back in that spot. i told my husband i was pregnant and he didn't believe me but sure enough! lol btw- icing my back helped.
lower back pain be a sign of pregnancy? my lower right side of my back right above my hip. it is a constant dull pain but with sharp intense bursts periodically. i am a day late on my period right now took a test that showed negative. could i still be pregnant?