If you stop taking the pill immediately, you will bleed within a couple of days. Of course you will not be protected against pregnancy then. If you have time (and can take other birth precautions) stop taking the pill now, and you will bleed, then you will have your period before you go on vacation and be fine for the vacation time. If you are taking a higher dosage pill (30 or 50 mg) you can try and "skip" your period by not taking the "sugar" pills in the packet. These are the seven pills you take when you have your period. Usually you take these last in a month's packet. By not taking these pills, and moving straight onto a new packet and the active pills, most women dont bleed at all and therefore can go months between periods. Of course it will depend on how strong the pills are against your body's normal hormones. I was taking 20mg dosage pill, and when I tried to skip a period, I instead got a very light flow for three weeks! Eeck! A stronger dosage will make sure you don't bleed.