When and how do you break your pregnancy news to your boss?

We were having a catch up that time. After discussing few work-related stuff, I surprised her with my 1st ultrasound print - while I was in tears. Crying because that time, I am still not so happy about my pregnancy due to lots of factors (unexpected, fears, parents disappointment at first, partner not ready as well) and I felt that sooner I am causing inconvenience to our team. As I am the sales manager, for sure my pregnancy could hinder me go visit clients in further cities, attend long hour meetings, do physical work that would exhaust me etc. But she scolded me and explained that there is nothing to worry about as my early announcement is a big help to plan out things and that my baby is a sure blessing. In all fairness, my boss took care of me back then. Sharing your pregnancy to your employer is a must. After all, your supposed relationship should be a win-win situation. You let her know your situation and she lets you know her expectations and manage your limitations in this crucial times.