32 Year Old Female, Regular Periods, Wants To Pre Pone Periods. Medication Which Can Be Used?

Hi. I am a healthy 32 yo female who has a regular 26-28 day menstrual cycle. My LMP was 21 June 2012. I have two very important events coming up right around the time when I will be starting my next period. The first couple of days of my cycle, I have painful cramps and nausea, and that s perfectly normal for me. This, however, will really affect my performance at the start of a very important work inspection. I want to try to start my cycle early and have read that using emergency contraception can help prepone menstruation . I am not currently using any birth control since I m in a long-term monogamous relationship and my partner has a vasectomy . Can you give me advice on how to get my period early so that I don t worry about it during my inspection? I would get advice from my gynecologist but she frowns on manipulating the menstrual cycle.