LOVE LOVE LOVEEEEE! Definitely size up.. I'm curvy  6' tall 190lbs and 36D. Normally wear a 12 and went with a 4x because normally when swim comes from China a US 12 is equivalent to a China 4X, and even a XL would only be good if you're US 6.. I'd say it's safe to follow this below and you'll be good :-)

S=  0
M= 2
L=  4
XL= 6
2X= 8
3X= 10
4X= 12
5X= 14/16