Just start whenever. It won't hurt anything.

If you don't have a period than start a Sunday dating. Thats what I've been told. But I'm sure you can start anyday of the week, the pill should start helping you have regular periods. Just make sure if you are having sex to use a backup method for the first week forsure and some people say even the first month. Good luck

Yeah, the sunday start is nice if your package is labeled starting on sunday

I started it as soon as I got it. A sunday start is nice because it goes along with the labeling on your package. However, as long as you take your pill every day on time and STILL USE A CONDOM (if you are having sex) for the first 2-4 weeks (depending on what the instructions in your pack says), you will be protected.