Boobs

So im just 10 weeks and my breasts are alteady starting to get bigger, not that they arent already huge. So i was wondering, i dont want to buy like 5 different sized bras over the next few months, so what size do i get, im currently a 34DD and they are starting to get uncomfortable in my bra. I really need something bigger but also big enough that when my breasts continue to grow they will have room and i wont be running to the store to buy another bra..