Is my wife's Hajj circumambulation valid, given that she took medication to prevent menstruation, performed ablution before the circumambulation, then found a spot of blood half an hour into the circumambulation, and nothing else came down until she stopped the pills and her period began in Riyadh? And is anything required of her?

This drop of blood is considered menses if its duration, combined with subsequent bleeding and any interspersed days of purity, does not exceed fifteen days. The wife's circumambulation (tawaf) is valid because if an event could have occurred at either of two times, it is attributed to the nearer time. As long as it is possible that the drop appeared after the tawaf, the tawaf is deemed valid in all circumstances.