Well, having just delivered my baby in September and having tried (emphasis on the "try") to be paleo the whole time I would say that the whole "listen to your body and what it wants" is (no offense) kinda ridiculous because as well all know who already eat paleo, your body will trick you into "wanting" things it doesn't need just based on a crazy roller coaster of hormones and sugar. And that is when you AREN'T pregnant! So, here is what I learned in 9 paleo months...
1. If you have a food aversion, it may change later, but if not... don't sweat it. I couldn't eat eggs from before I knew I pregnant until the day I delivered... who knows why... just made me want to retch.
2. Try to be as paleo as possible because it IS healithier, because gestational diabetes is a terrible complication to have and your body will be more sensative to insalin after a long period of the paleo diet prior to pregnancy, and those pounds are going to pack on in the final trimester no matter what you eat so if you eat whatever you want in the first two trimesters than by the third it will be insane...
3. As long as you are eating healthy, don't stress about weight gain. I ate mostly paleo the whole time and STILL gained 55lbs, but I WOD'ed until the day before I delviered... whatever you do, DON'T quit the gym unless it is medically necessary. It will be your savior when you feel miserable and fat in a few months... Most weight gain is just genetic and there is not much you can do about it and if you eat healthy, it WILL come off post-partum.
4. Sounds like you are in your first trimester with all the food aversions... that will change! I could only drink chocolate milk for breakfast my first tri (SO not paleo) but by 14weeks I felt much better and could eat realy breakfasts again (just not eggs!) So, hang in there... your tastes will broaden...
5. Finally, making sure you take your prenatal (I used Perfect Prenatal by New Chapter Organics bc it was guaranteed not to upset your stomach!) and in your final trimester at least 1500 mg of calcium daily is super important... if you don't take that in (mostly in a supplement because you would have to drink over a gallon of milk daily to take that amount in through whole foods) your baby will rob your body which will hurt you in the long run. Also, if you can keep down your fish oil than you and your baby will both benefit: Omega-3's for baby's brain and reduced inflamation for you! :)
Good luck, girl! I agree with the other posters, whatever you can do is worth it, but I will say... you get pretty large and in charge by the end and not putting on pounds at the beginning can help with that a little (I swelled up crazily but that was a whole other issue... water weight is just as uncute as real fat! Lol)... good luck & congratulations!! :)