Bumps under breasts

[Pink Petals]

Overnight, I developed some bumps on my chest. There are maybe 10 or so. One above my breasts and the others underneath. They look kind of like mosquito bites and they itch. No other symptoms.

Of course I googled it and came up with breast cancer so I am freaking out. Could it be mastitis? Mosquitos typically don't frequent my bra, so...