Breast pump for expressing milk from a breast, comprising at least one breast cup (2) for receiving a breast, a pumping system (10) in fluid connection (11) with the at least one breast cup (2) for applying a negative pressure on said breast and a detection unit (3) comprising at least one sensor for measuring a parameter during use of the breast pump (1), wherein the breast pump (1) is adapted for optimising breast pump settings by actively controlling at least one breast pump pumping property, based on measurements of the at least one sensor (4, 5), during a period of use of the breast pump (1), in order to personalise operation of said breast pump (1) for a particular user.