Women all around the world are concerned about their rights as a pregnant woman, and the case is not different in California. It is completely understandable that a lot of women do not tell their boss about their situation because they have a fear they will be fired.

But on the other hand it is not fair if you hide something like that, so you should definitely let your employer know about your pregnancy, especially when your pregnancy affects your ability to work.

When you decide you will do it, you can do it in an e-mail, writing a formal letter and what is even better if you decide to do it face to face.
If you decide to do it verbally you should document that statement in some form of writing just to have a proof that you have informed your employer.
Luckily the California Fair Employment and Housing Act prohibits an employer from discriminating anyone because of her or his sex. In that case sex means childbirth, pregnancy, breastfeeding and any other medical condition related to pregnancy.

Also what is very important to mention, because a lot of employers don’t know about this law, and that is that California’s Pregnancy Disability Leave Law covers morning sickness or any other type of medical condition you have simply because you are pregnant. Also if you have condition such as post-partum depression that is something law will definitely cover.
Every change you encounter during your pregnancy must be discussed with your employer, because only in that way you will be able to get all the rights you need.