Back labor before contractions ?

FTM here!

I’ve been having back and butt pain for about 5 hours now. I’ve had sciatic pain for the past couple of weeks but this is much more painful. I’m not sure if it’s back labor since I’m only 33 weeks. I took a hot shower to help but i keep getting cramp-like pains also. But i don’t feel like they’re intense enough to be real contractions. I’ve been in bed all night (other than the shower) not able to really move much without being in pain.

Any suggestions? Thanks in advance ladies!