Well depending on what type of resort your choosing would be a factor but if it is a typical large all inclusive resort I don't think you have to worry about the rooms being sold out this early. Also if you have chosen a resort see if your able to put down a deposit to hold your wedding date but make sure it is refundable. I initially had chosen Dominican Republic and had put down a deposit at a resort and everything and then ended up changing my mind and going to Cuba. The first resort had no issue with refunding me and then the one in Cuba didn't even require a deposit.
Also not to sure what country you are in but I know in Canada a lot of the vacation suppliers offer a one time price drop up to 60 days before departure.
So as much as I know how hard it is to wait to book I think I would if I was you at least for a month and see where the prices go. Also try out different TA's. I managed to get a way lower rate from an online booking site I then took that rate back to my TA and gave her the option to lower her quote to me which she did happily or I would move on to someone else. It saved me $150pp!
Sorry to ramble and I hope this helps I just know that this part was probably the most stressful for me because I just wanted to get everything booked and settled!!