There is one thing - you know your LO is back to back and you've been through labour before. So at least if things get really bad you know it's a particularly bad labour and can ask for pain relief. I didn't know DS had gone back to back until afterwards when the MW realised as he came out the opposite way round from how he'd been lying. He was my first baby so I went along with everything they said ie go for a walk, have a bath (owwww!), you don't need pain relief this early , etc. and didn't ask for help as I thought what I was experiencing was just normal. It was hell, so what I'm saying is don't be a martyr to it - if it's loads worse than you expect then get pain relief fast!