Depending on the type of coffee you are drinking, the amount of calories will differ significantly. Adding extras such as milk, sugar and syrup will all directly affect the calorie content of a coffee. A standard cup of black coffee (around 8oz) contains 1 calorie, but a cappuccino for example can contain anywhere from 60 to 160 calories, depending on the type of milk you take and the size of the cappuccino. For a low calorie coffee, switch the sugar to sweeteners, and switch full milk to skim or soy (or cut out the milk altogether!).
You can drink coffee while you are pregnant, although it is recommended to limit the amount of caffeine you consume to around 200mg – which is about the equivalent of two mugs of coffee. Drinking more than this while pregnant could increase the risk of miscarriage, or having a baby with a low birth weight. Ultimately, the decision to consume caffeine is up to you, but you can cut down by switching to decaffeinated drinks and having smaller cups of coffee.