underarm bulging - any solutions??

I'm going to a wedding Friday and I bought this beautiful cocktail strapless dress. The problem is that I have some bulging LOL blush:
by my armpits (best way to describe it). the dress is a size 0, but when I tried the next size, it was too big. I was told to wear it with the nubra and it would take care of it. Is it true?