Paper analyses relationship between advances in age at first attempt to conceive and apparent fecundability defined as detection of a pregnancy. Analysis focuses on biological consequences of age shifts in fertility schedules in contemporary low fertility societies. Due to age specific decrease in biological ability for natural conception, women may experience increase in waiting time to pregnancy measured as interval between onset of deliberate attempt to conceive and pregnancy detection. Fecundability data come from two waves of Polish GGS survey collected with a short retrospective questionnaire. Using hazard regression model we have found significant increase in waiting time to pregnancy among women aged 35+, slight increase among females aged 30-35 and no effect for younger females. Results are in line with other studies which suggest that postponement of reproduction beyond age of 35 might influence probability of conception, transition to higher parities and childlessness. Taking into account current fertility patterns, age-specific decrease in apparent fecundability might have only moderate effect on observed fertility rates and realization of fertility intentions. However, systematic increase in age at first effort to conceive might be potentially a factor in a reproductive health especially among social groups which are in the avant-garde of fertility postponement.