Does coffee make me more or less likely to get pregnant?

Miscarriage risk. As far as we know, coffee intake has no effect on getting pregnant. One study found an increased miscarriage risk at a caffeine intake of two cups of coffee a day or more (or 5 12 oz caffeinated sodas) ... So we recommend one cup of brewed coffee a day and decaf for the rest. Espresso drinks are much higher in caffeine and should be avoided unless decaf; tea is lower in caffeine than coffee.
Varies. More than two cups a day seem to affect the way an egg is picked up by the fallopian tube. If you are trying to conceive, best to stick to 1-2 cups per day.