I had one before being given the drip to speed up my contractions, as I was afraid it was going to be more painful.
Getting it wasn't so bad, and at first it was great. Then it wore off on one side, then the other too. The pain was horrendous, and the doctors wouldn't do anything about it/wouldn't believe me! I couldn't move about because I'd had it, and I really wished I'd just kept active instead.
No way am I having one this time, you couldn't pay me. It's a home birth for me now.