BC and condoms or lack of

Okay I know this might be a silly question but I honestly don't know how this works exactly.
​I'm currently on trivora the pill BC 
​although I don't take it everyday at the exact time sometimes I forget and take it a few mins late. I started taking the pill in Oct'13 
​Here's a few questions I hope someone could help answer
​1. If you miss a pill how long does it take for the pill to become effective again? 
​2. If your on the pill does your partner still have to wear a condomto avoid   pregnancy or are they allowed to ejaculate in you still without the risking pregnancy?  
​3.  And if he uses the withdrawal method, should we still be worried about pre-cum and the possibility of getting pregnant that way? 
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