How many periods is it safe to skip in a row by running packs of the pill together?

I recently switched from one brand of the pill to another, and to do this I ran the 2 packs together, so I had no period. Next week I'm due to go away with my bf, but something else is due as well so would it be safe to go straight on to another pack, considering that would mean taking some form of the pill for 9 weeks with no breaks? Also, is it likely to work or will I bleed anyway?

Any advice greatly appreciated!

Sadako

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