PregAid is a basal body temperature (BBT) measurement system with the function of recording. It is mainly used for scheduling conception or contraception by women in childbearing age. System obtains the BBT data from thermometer via bluetooth, draws BBT curve and marks reminding of suitable pregnancy automatically. Users achieve the goal of effective pregnancy or safe contraception by observing the changing of BBT curve in a menstrual cycle and comparing it with the curves in the rich BBT curve library providing by the system itself.