Yes, it is possible to get pregnant naturally at 49, although it is rare.
While not common, spontaneous pregnancies resulting in live births after the age of 45 do occur. A study involving 209 women (0.2%) who had conceived spontaneously and had their most recent delivery after the age of 45 years showed that some women in the study population delivered at age 49. The age range for the last delivery in this group was 45-49. The mean age at last delivery was 45.7 ± 0.9 years. These women also had a high mean gravidity of 11.5 ± 4.5 pregnancies.
This indicates that while statistically uncommon, natural pregnancy and delivery at 49 is a documented possibility.
