Aw, mahirap yan mama! Since you're 9 weeks in, it could be plugged duct or just uneven milk flow, a few of us had similar experience, parang kumikirot lang talaga on one side, but please check with your OB or lactation consultant kaagad kasi kung tumatagal yan, baka may mas kailangan na attention, you know? In the meantime, warm compress before feeding and massage that side gently habang nagpapasuso to help with flow. Sana mabilis mawala na, hang in there!