Is there any way you can stop a menstral cycle before a big event?

Yes: It is possible to stop or more your period to prevent it occurring during a big event. This is often done with birth control pills. It is best to do it 2-3 months before the event (more likely to be successful) rather than waiting until the last minute. Contraceptives can be used to decrease period frequence or stop them all together as well. Talk to your doctor about your options.