Statistical models of fertility studies play a crucial role in understanding the biology of conception. Heterogeneity in women and men's requires specific statistical methods to be used in order to allow for the variability in behavioral and physical characteristics, as well as for the variability in frequency and timing of sexual intercourse and for the progressive selection of patients during the fertility studies that provide data. A review of the most used models is offered, starting from classical population models, based only on aggregated data we then discuss time to pregnancy models and the models that predict the day-specific probability of conception.