What can I do to get contractions started?! HELP!

Katie
I left L&D about four hours ago! I was 2.5cm dilated and 60% effaced. They sent me home because I wasn't having regular contractions. Since I've been home- I've been in pain. I still am not having contractions though! Any ideas that don't require loads of energy to get contractions started?!? I'm so miserable!!