K.,
I cannot speak to the boob thing. I do not believe you'd be depriving your child of any nutrients, however, but I'm not a medical professional, so I don't actually know.
I want to speak to the sex issue. I am divorced now (after 21 years of marriage), and the sex during pregnancy stuff happened a long time before the divorce, but it was only during the separation and during the divorce that I found out exactly how my husband was feeling during that time in our lives together. He didn't tell me at the time, but he resented me and even the baby because I wasn't willing to fulfill that very important area of need for him.
As you know, men are sexual beings. They have so much of their emotional and physical self tied up in the sexual act, much more than we do as women. When a woman is not interested in having sex with her husband, it really doesn't matter what the real reason is. The real reason may be that you're not interested or that it is uncomfortable, but no matter what, your husband will take it as an insult and it will hurt him inside. He will wonder WHY he can't make you comfortable or interested, and if he can't, he will doubt your love for him and may come to resent you. For my husband and myself at least, it was a poison that seeped into other areas of our lives and eventually destroyed our relationship.
I'm not accusing your husband of anything or even suggesting that he will do this, but as a result, my husband sought out other lovers who were interested. I'm not saying it was my fault that he did what he did. He had no excuse, however, I did leave him in need, and instead of him attempting to fulfill his need with me, he chose an easier path.
So, I'm asking you to find a way to be interested. Maybe it isn't about the actual act of sex, or maybe if you start with other things, it might get you more interested. Here are my suggestions.
Valentines day is coming up, and as a result, there are a lot of little hokie valentines things in Rite Aid, for example. Such as dice or lottery tickets or love coupons, etc. One set of dice has "rub my" or "touch my" on the faces and the other has a body part. So, you roll the dice and it might come out "rub my" and "arm". Another set has "Lets kiss" or "lets hug" on the faces, and the other has a location, so when you roll them, they might say, "Lets kiss in the closet. If you put a little fun, laughter and anticipation into the it, it just might spark something.
Another suggestion is to get a book from the library or somewhere that might suggest alternate positions that might make it more comfortable for you. If he sees you interested and trying to meet this need for him, it should score lots of points for you, even if you try something you ultimately don't like and don't want to repeat.
Finally, I think it is more about trying to meet his emotional needs of wanting to be intimate with you, wanting to be connected with you, and wanting you all to himself. He wants to be the focus of your attention. He wants to be the object of your affection. Even though you have children together, it isn't enough. He hardly ever gets you all to himself, and he wants to show you how much he loves you, is thankful for you, admires you, and finds you beautiful and sexy.
Don't take his interest for granted and don't push him away. You have promised to love him for better and for worse, and in sickness and health...so do it. Even though you are tired and worn out and your SAHM and pregnancy is physically exhausting for you, find a way to cherish him and what he means to you, and what he will always mean to you.
And no matter what, do not go down to once or twice a month after the baby is born! Keep your relationship special and vital, and you will still have each other long after the children are grown.
If anyone had been this frank with me when I was a young wife and mother, it might have saved my marriage.
I hope it helps,
L.