Being on period for 18th birthday? 2 packs of the pill in a row?!

Right well im currently on the Microgynon 30 pill to help regulate my periods. Ive been on it for maybe around 4 years now. I used to have very irregular periods and even had 2 in one month. So anyway, my packet lasts for 21 days and then i start my period. But my birthday is in just over 21 days. I was wondering if it would be alright to take 2 packs of pills in a row...without a break for my period. Ive read up about it a little and people have said they have done it and that's its been fine. But I want to make sure it will be ok. Its just that im planning to go to the beach for my birthday and I would rather not be bleeding everywhere in just a bikini with nowhere to change the tampon. Thanks :) x