If those breeding dates are correct, she's likely just beginning her udder changes. That is why I say I like to check several times a day, not always at the same time either, because they increase and decrease a lot, gradually building, and near the end, they get hard and tight (not necessarily BIG), and STAY that way. Leading up to that point though, they fill some, harden, soften, then sometimes one side may be firm and full, the other not. LOTS of constant changing preparing themselves for their new arrival. But yes, always best to be prepared ahead of time, because you just never know!!!