Is it bad to stop birth control for one month and then start again?

No harm: But there is no benefit either to such a "rest". And, obviously, you don't have birth control for a while.

Define "bad": The pill works by providing a constant blood level of hormone that prevents egg release & makes your womb less favorable for pregnancy. Stopping allows the process to return to normal. Since many OB's recommend a second form of BC when you start the pill for a month, just to be safe, skipping a month just places you at risk for a bit longer. If it doesn't matter to you, it doesn't to your body.