It's ok to start your next pack right after you finished the other(if you want to skip a period). There's no problem even if you took it on the 4th day of rest since those seven days are still under the pill's effect(if used as cotraception).
But in your case, you want a regular menstuation. Then, you should take it on the right schedule. You should be having your period on every of the seven day rests. It doesn't matter if it started late or not,because it will soon be regularized after finishing a few packs.
@renesme (twilight fan?)
If you are after contraception, the pill's effect is after 14days. But if you take it on the very first day of your period, then it will take effect right away. You will have your period after the 21st tablet. That is the purpose of the 7day rest. Usually, periods don't come at the estimated time on the first and second packs. So there's no need to worry if you had your bleeding earlier or later since you've just started.
Hope this helps!