Hi Chloe, Not sure if this could hurt you being pregnant, but vitamin B 6 should get your juices following again apart from the odd couple of days a month, do a trial and if it works you may have to stay with it, for life, but dont overdo them.
Good Luck
When your pregnant your body changes alot in more ways than just size. Your hormones imbalance and change and thats why pregnant women are usually very emotional and irritated easily along with other problems. Its normal for your vagina to act differently and dryness can be an issue for some women. Your completely normal so relax. You should try explaining this to your partner and Im sure he'll understand since after all you are carrying his beautiful baby. You should try getting a good water based lube to make sex more comfortable for the both of you.