I've not noticed antibiotics having an impact on supply, but I was going to say the same as Barb, because there have been blockages the usual pattern of empty breast-signal to make more milk-more milk made-baby feeds-empty breast has been interrupted. Because your breasts probably haven't been 'empty' as such your body hasn't been getting that message 'I'm empty, fill er up thanks' and your body is thinking it can slow down the milk production. But yes, keep feeding her as much as she demands and your breasts will come to the party!