Does sciatica pain always radiate down your legs?

Irene • Due date Aug ‘18 but she came July ‘18 🙌🏾🙌🏾🙌🏾 Late Term Preemie 💕🌈💕

Hi!

I’m trying to figure out if this constant back pain that I keep having is sciatic pain? Sometimes it’s a sharp lower back pain and it radiates to my butt. Is this sciatic nerve pain? Or does that usually occur later in pregnancy like third trimester? I do get prenatal massages but it only relieves me for about a few days and I try to stray away from Tylenol unless I desperately need it. I’m currently 24 weeks. Thanks in advance!