Hi -- I'm on seasonale & when I miss two pills I start bleeding.. usually only for a few days, but everyone is different. Anyway, I agree with Monkeyflower...
Just keep taking your pills (hopefully the bleeding will stop) & then you'll have your "period" and hopefully you'll be all set when you start your new pack. If you start bleeding excessively, I would call your DR just to be safe.
It's not unhealthy. When you use continuous birth control to skip your period, the lining of your uterus becomes very thin and unstable, which can cause spotting. Seasonale gives you a break every three months to minimize this effect, but it still happens for some women. I think in your case it was probably also affected by missing a pill (or two, I wasn't sure from your post). Personally, I'd keep going and see what happens after your period.