Boobs won't stop growing!

I've already had to buy 2 different sizes of bras, and I'm only 20 weeks! Right now I'm a 40 DDD and I have a feeling they are just going to keep getting bigger( which sucks because good bras aren't cheap!) My husband thinks it's the greatest thing ever, but he doesn't understand the struggle.Does any one else feel like their boobs are just gonna keep growing until they explode?! Is it more difficult to breastfeed with large breasts?