Must I make up the days I missed in the last Ramadan along with expiation, knowing that I broke my fast due to postpartum bleeding (nifas) which turned into light yellowish discharge, and I thought that complete purity (tahara) is only achieved with complete dryness?

Yellow or brownish discharge connected with blood is considered nifas (definition) (postnatal bleeding) as long as it occurs within the forty-day period. However, if the yellow discharge appears after the cessation of blood, there is a difference of opinion regarding its ruling. You are not required to pay kaffarah (definition) (expiation) merely for breaking the fast. Instead, you must make up the days you missed before the next Ramadan (definition). If you delay making up the fasts without a valid excuse, knowing the ruling, then kaffarah is required in addition to making them up.