Lump in my left Breast

Brittany • Mommy to a wonderful 12yr old boy, 9yr old boy 7yr old girl 6yr old girl and 3yr old girl. Due March 11th 2023 with a boy.
I have a lump in the spot I know fills with milk b4 my let down. Even after i pump it's still there. It hadn't been there it just showed up yesterday. It doesn't hurt and everything I have looked up on the Internet says mastitis. But there isn't any pain. any one else have this? I've tried a hot wash cloth and massage and it won't go away .