Rupert01~ When you get on the pill it changes your period usually. That first 3 months your body is getting used to the hormones on the pill, and that extra long bleeding sounds like a side effect of the pill. It should go away over the next couple months.
Did you continue your next cycle of the pill after that week? Make sure you follow the directions even if your still bleeding because if you don't you may get pregnant.
My best friend and I were on the Depo shot at the same time and had different experiences. She bled for over a month straight whereas my period stopped.... hormones affect everyone differently. Sometimes side effects can actually mimic pregnancy because depending on the formulation of the pill/shot/patch....
The hormones trick your body into thinking it's pregnant so you don't ovulate. or at least that's how it's SUPPOSED to work.. it doesn't always work.
Also, if your on the pill and tak antibiotics at any time, use a second form of contraceptive (like condoms) during the time you take the antibiotics and for at least 10days afterwards. Because antibiotics can cause birth control to be less effective.
If you have any other questions on birth control, just come over and post on the Pregnancy 21-34 community board. Just label it OT (for off topic)and type your question.. there are women over there who'd be happy to help you if you need it.