Do breasts have a 2nd puberty?

So I missed my period for a month and was freaking out because my boobs have gone up half a size. The were noticeably different & sore. I took a test which was negative and then got my period after. It usually comes after I waste money on a test lol But my breasts are still bigger. They swell a little before my periods, but not like this. My little fin is now the same size as my my other. I also just turned 26, so im wondering if our bodies go through growth spurts around this age?