Breastfeeding?? I am confused ?

I am expecting a baby and it is my first.. I am really thinking about breastfeeding and everyone has told me that it is healthy for woman and her child too (breast feeding child for two years - its very long period).. But some people told me that after breast feeding, breasts start to look ugly and not as fresh and good. Like they start to age very soon and before time start to look old.. Does it really happen due to breast feeding?? And what about breast pumps?? Are they bad for health?? And if they are not do they help prevent the breast sagging n becoming old? I also heard that breasts become big too after breast feeding?? Is all that info really true??