Gage, I feel a great connection with SJH's post!
With DP, everytime he touches me, I know it's because he wants it to end up as sex. He knows that I don't often want it to end up as sex yet he always takes it there, because he thinks he's convinced me that I want it after all. I'm not dead against it, I'd just sometimes rather conserve my energies and snuggle. I don't know if this is the case with you, I know that DP has admitted it to me - the hoping to change my mind bit.
So, yes, in just you explaining about the shower or massage has made me want to curl up into a ball, just thinking of the chain of events!
I'm breastfeeding, so I expend a lot of nurturing energy during the day AND night. I call it 'putting out'. When DP wants me to roll over after DS has fallen asleep, I just want to snuggle into my little boy, with my DP snuggling my back so that I feel looked after. Next thing I know...hello!! So then I put out on both sides of the bed, so to speak. It's tiring. So, I am not being a doomsayer, just warning you that it could continue after the baby is born, depending on which way her hormones sway. Also, I very much agree with Rosehannah that if you can start showing NOW that you can demonstrate your love for her in lateral ways, she might muster up some mojo on her end of things. My DP is very sporadic in his house cleaning efforts, so that mostly it's me doing everything, with him putting in a big burst of energy every once in a while (sorry, it doesn't buy him enough brownie points when I'm red in the face from asking before some help is rendered!!). By the time we're DTD, it feels like I'm putting out on 3 levels. It's no wonder that I'm seriously behind in my studies! But more about me (hee, hee!)...
I realise that guys equate love with sex and to suggest that your DF's way to reinforce that she loves you would be to DTD could severely backfire. When it merely sniffs of an 'if you loved me you would DTD', it becomes a transaction. It is also emotional blackmail and is not very compromising. Please don't discount the power that hormones have to switch off her mojo - the mind can be very, very willing on one level, and on another very, very unwilling. Two competing states of mind to host at one time...it's not fun! Sex should never be granted out of guilt. I have and I end up feeling tired, and hollow - no-one wants to feel like a vessel and pregnancy (and to a lesser extent, post-birth) is the perfect time to feel like one!
I think it's important to impress upon you fellas that this is so, so common. None of you guys ever admit among yourselves to not getting any, though, so you dont' realise how common it is. It's not a rejection of you, it's a rejection of sex.
I am privy to the way you guys work, I'm in a fire brigade. DP tells me how a couple of the fellas talk about DTD all the time. Eg "x says their sex life is pretty good", or x says "can't complain, she's pretty good about it". Then I get together with the girls, who don't know that I've heard these things, and x's wife blows his cover! Even if he IS getting the sex, she's doing it out of a sense of duty, because she feels like me - like she's putting out all over the place! So, x insists everything is hunky dory and his wife tells me she has to slap him away and she feels guilty.
Like the others have said, communication and consideration will get you far. And mentioning to the MW without talking about it first will lose you so many brownie points!
In a nutshell - it is very, very normal for her to not want to DTD and it has very little to do with her feelings of love for you (she probably feels that she is carrying the ultimate symbol of her love for you).
I hear your pain, I feel hers