Short answer: Conflict, tension, heartache... *BUT* please read on!
Short answer: It's grey, but on average 8-12 days (that is, if your goal is to avoid pregnancy).
If you’re practicing NFP to avoid/delay pregnancy, you will generally need to abstain from sex (including all genital contact) an average of 8-12 days every cycle depending on your cycle length. It also depends on how open or closed you are to getting pregnant. If it would be wiser to avoid pregnancy given your situation (like for medical reasons), perhaps a lengthier time of abstinence would be advisable and healthy. Whatever the case may be, we can help you determine what your fertile window may look like. In general, whether avoiding or achieving, we are fans of abstinence. Life will likely demand of you ample enough times of abstinence, but even if you don't need to abstain we would encourage you to try it occasionally. Abstinence will challenge you to look at your motives for sex, to be considerate of each other, to communicate, to express your love and desire in other ways, to live your intimacy more authentically.
Short answer: It can, but it doesn't have to.
Short answer: Maybe. The answer depends on whether or not you are open to having a "honeymoon baby".
Short answer: Talk about it with your spouse.
Many life events require abstinence, whether it is after a baby, sickness or separation due to work or otherwise. Abstinence certainly can be difficult and although NFP offers a holistic approach to your health and overall well-being as individuals and as a couple, we would not ever want NFP to cause division between you as husband and wife. Talking to your spouse about alternate ways of showing affection during her fertile time, and being purposeful in doing so, (whether abstinence is actually called for or not) will help you get through those times of the month when you do need to abstain. Remember: abstinence makes the heart grow fonder and the honeymoon phase is just around the corner. We don’t want to sugar-coat it: times of abstinence may indeed be challenging, but we encourage you to at least try it. It's a muscle that can be strengthened and ultimately can help you to grow closer together.