I'm in my third trimester with only 5.5 weeks to go I have been dealing with sciatica since the beginning if it Hurts on one side lay on the opposite side with a pillow or 2 in between your legs this helped for me
At the end of my first 2 I had horrible constant back pain. It turns out I had a ton of fluid and over 9lb babies that were at fault lol. As far as being in labor I felt nothing until about 45 min after my water broke (unusual but not unheard of).
My inner hip joint/cartilage/capsule hurts bad, when taking side steps or moving in bed.
Happened to me my first pregnancy. I was in labor. Went to the hospital and had my son the very next day.