You've had your period for over a week because you tried to skip it using triphasic pills. You can only skip periods if you are on monophasic pills. Triphasic means that there are 3 different hormone levels in the pills depending on which colour pill you are taking (for example, i'm on triquilar, also triphasic, and the brown pills are one hormone leve, the white ones are another, and the light brown ones are still another). Monophasic means that, throughout your entire cycle, you are only taking pills that all have the exact same hormone level. All the pills will be the same colour.
Every time you try to skip your period with triphasic pills you will mess up your cycle. If you want to skip it sometimes, talk to your doctor about monophasic pills.
I really doubt it's a miscarriage. It's probably just because you screwed up your hormones by skipping the week off. If you're worried that it might be, though, talk to a doctor.
I hope this has helped a bit!