Bad Back & Epidural

I'm 24 weeks pregnant with number 3 and starting to consider if I want to have an epidural this time. My first two were only with gas, so I know what I'm in for 😂 I have a couple of slipped discs in my lower back and don't know what the risks are or if it would even work, any advice?

I have my midwife appt this week so will ask them too