What is the chance of getting pregnant at 40 vs 35?

Lower. There is a gradual decline in fertiliy between ages 35 and 40, then a sharper decline after 40. There will be increasing chance of miscarriage with advancing age also.
Lower. The odds of pregnancy at 40 are statistically lower than at 35. While you may be an exception, there's an exponential drop in success after 35 and especially after age 37.