Gentle stretches can help, sometimes -- check especially to see if the muscles that run on either side of your spine are tight. If they are, see if you can either stretch them out gently, or get someone to give you a good backrub.
Warm or hot baths can be really helpful too, and some women find that masturbating to orgasm is a good way to relieve cramps at least temporarily. Deep breathing and relaxation exercises are also also a good thing to do whenever you're in pain, as you'll hurt more if you're tense.
Copyright 1998, 2014 Heather Corinna/Scarleteen
Scarleteen.com: Providing comprehensive sex education online to teens and young adults worldwide since 1998
Information on this site is provided for educational purposes. It is not meant to and cannot substitute for advice or care provided by an in-person medical professional. The information contained herein is not meant to be used to diagnose or treat a health problem or disease, or for prescribing any medication. You should always consult your own healthcare provider if you have a health problem or medical condition.