I am not sure about the authenticity of the links you posted, but if you haven’t yet done so, PLEASE read GOOD NEWS ABOUT SEX and MARRIAGE by Christopher West. It is taken from the Pope’s writings so is VERY Roman Catholic but VERY easy to understand. It should answer your questions (even embarrassing ones) and is real easy to read. I would suggest you and your husband read it together.
NFP is different that ABC because in using ABC, you are attempting to separate the act of sex from the act of conception. NFP does not do this.
Good luck with the little ones!