What Causes Swelling In Breasts?

Hello.... I was just wanting to discuss a few signs I've been researching. A few months ago I switched my birth control from the IUD to the pill. I've onlt had one period on the pill and it was only 3 days long and lots of spotting which is not something I'm use to because when I had the IUD it was 7 days and VERY heavy. I've also had to go up a bra size which is weird to me because I've been the same size for like 6 years and I figured it was because I got back on birth control that had hormones. But they feel rather swollen to me and they are kind of tender around the sides. My nipples are also like a purple color and I'm not sure if it's because my breasts are growing. And I've recently been dealing with some inflammed lower back muscles that are pinching a lower lumbar nerve, but my Doc says its from sitting too much. Now, I'm a week and a half away from my period, I'm cramping, my lower back hurts, The anti-inflammatories I'm taking arent working, I dont feel like I'm getting enough sleep at night, and I'm craving greasy foods. But its hard to tell because I'm assuming its cuz I'm close to my period.