Why is this even a question? I don't see a reason for any hesitancy from your side. In fact you should have informed your superior(line manager and project manager both) immediately with pride, confidence and joy. It helps you as well as the team so that they can plan accordingly.
Women should never feel hesitant with these important issues.
And compared to other places Europe has better understanding of women's rights.
There's 2 aspects here. First is the communication as you would to friends or acquaintances. This is kind of optional people will find out one way or another but it really depends on your interpersonal relationships with your coworkers managers and such. Are you friends with these people do you talk about your personal lives and so forth.
The second is dealing with the impact to your actual work schedule time off and so forth. This is very dependent on the laws where you reside and the company policies you have to deal with. Generally pregnancy is considered a form of medical leave but again it depends on the specifics of your country. I would approach it in the same manner you would for any medical leave. Become familiar with your company's policies regarding leave paid leave unpaid leave etc form an idea of what you want to do and contact HR department first and discuss it with them. Generally HR should be discreet and discuss with you your options and so forth and at this very early stage not necessarily discuss it with your direct managers until you're ready. once you formulated a plan on your leave time expected return and so forth and have it worked out with HR then it's probably an appropriate time to take that to the manager or managers so they can work with the schedule.