What are these?

Summer

So please excuse me for being a little ignorant but I absolutely have no clue what these bumps are. I know they are nothing to be worried about but I don’t know why they are showing up. I’ve never had them before. Idk if it’s relevant but my period is due in 6 days and right before these showed up I’ve had very sore nipples. It’s went away today and that’s when I noticed these. Anything you guys know would be super helpful ❤️