Re: The pill- period at the wrong time?!
I can think of a couple of reasons why this could have happened...
What kind of birth control are you on? I'm pretty sure that you can't use the triphasic birth control to skip a period. Are your pills three different colours (a different colour every week)? Ortho Tricylen-Lo is an example of a triphasic birth control. If all your pills are the same colour, like Alesse is, then you can use them to skip a period.
The only other thing that I can think of is that sometimes when you try to skip a period with BC, you can get breakthrough bleeding, which can be light or it can sometimes seem as heavy as a regular period. But it usually doesn't last as long as a regular period.
Either way, I personally wouldn't worry too much and would continue to take the birth control as normal, but I would mention it to my doctor at my next appointment.