Back spasms ? 🤔🤔

After the my pregnancy w the twins I use to get back spasms everytime I bent over ( due to a previous epidural which messed up my back ) when I was pregnant w my twins the same kind of pain in my back happened but more severe ( like took my breath away type of pain ) and I started to have consistent contractions in the front not the back and now it happened last night and I can stand the pain I just can't move when it's happening and it's not frequent at all , it comes and goes .. Is this contractions or just back spasms .. ? I'm confused