When to go off birth control?

My husband and I want to TTC in a few months. I'm on a combination BC and was wondering how far in advance before TTC you all are planning to stop? I know you can technically get pregnant as soon as you stop but, I dunno, a part of me wants to see a few normal periods pass by just to make sure I'm...still normal? Also thinking of starting the prenatals soon. Ahhh...real things are happening!