How much bigger can my boobs get?!?

I'm only 6weeks 6days and none of my bras fit me anymore. I just fished out a measuring tape out of curiosity and my breasts have increased by 3.5inches already... how much bigger can they possibly get? I was a GG cup before, don’t even want to know what I am now. Will they just continue to grow? Should I even bother buying new bras if I will need to get a different size next week? Has anyone been in this situation? I know this sounds weird, but they really make me feel like a cow with udders, not a person. They also really hurt, so much I have nightmares about them.