You do not owe your employer your medical history. You owe them enough notice to plan around, at a time that suits you, in writing.

This is the part people lose sleep over. Not the forms, not the money. The conversation. Below is how I would approach it, and the words I would use.

When do I have to tell my employer I am pregnant?

Later than you think, and earlier than the deadline.

There is no rule saying you must announce a pregnancy at a particular week. What matters is giving reasonable notice of leave, and that is a much shorter runway than most people assume.

Two things move the timing. If you need accommodations, you have to raise it when you need them, not before. And if your role involves handovers or long projects, telling them earlier tends to buy goodwill rather than spend it.

What you should not do is announce it in a hallway because someone guessed. Choose the moment.

What information do I actually have to share?

Less than people think.

Your employer needs to know roughly when you expect to go out and roughly how long you expect to be gone. For medical leave they are entitled to a certification from your provider confirming the disability period.

They are not entitled to your test results, your birth plan, your fertility history, or the details of a complication. If someone asks, "the certification from my doctor covers what you need" is a complete answer.

Should I put it in writing?

Have the conversation however you like. Then send an email.

Not because you expect trouble. Because six months from now, when someone new is handling your file and the person you spoke to has left, the email is the only version that still exists.

Something as short as this does the job:

Hi [name], following up on our conversation today. I am expecting a baby in [month] and plan to begin leave around [date]. I will confirm exact dates once I have my medical certification. Could you send me the company's California parental leave policy, and let me know what you need from me and by when? Thanks.

That last question is the one that matters. It puts the next step on them, in writing, with a date attached.

What if my employer says twelve weeks and I think it is wrong?

Sometimes you will be told twelve weeks when California may entitle you to substantially more. Usually this is not anyone being difficult. National handbooks default to federal rules, and multi state companies often hand out the general policy rather than the California one. Here is why the real number can be closer to twenty nine weeks.

You do not need to argue. You need to ask a better question:

Thanks. Could you confirm whether that twelve weeks is CFRA bonding leave only, or whether it includes Pregnancy Disability Leave? I want to make sure I am planning against the right total.

Two things happen. If the person knows the answer you get it immediately. If they do not, you have asked a specific question that has to be checked rather than a vague one that can be waved off. Either way you are not accusing anyone of anything.

How do I ask for accommodations while I am still working?

Ask directly and keep it practical. Name the change you need and the reason, not your entire medical situation.

I need to sit for parts of my shift and take short breaks for the rest of my pregnancy. My provider can confirm this in writing if you need it. Can we get that set up this week?

Specific. Time bound. Easy to say yes to.

What should I confirm before I go out?

Get four things in writing: your leave dates as understood by them, what happens to your health insurance while you are out, your return date and what you are returning to, and who your point of contact is while you are gone.

That last one matters more than it sounds. Leave goes wrong most often when the person handling it changes and nobody tells you.

Separately, make sure your own filing deadlines are in your calendar. Your employer does not manage those for you, and missing the 49 day one is expensive.

The tone to hold

You are not asking permission and you are not asking for a favour. You are telling your employer about a period of leave you are entitled to, and asking what they need in order to process it.

Warm and matter of fact gets you further than apologetic, and much further than adversarial.

If you want to walk into that conversation knowing exactly what you are entitled to, start with your numbers. And if you want the actual words for your actual employer, that is what a session is for.

This is planning guidance, not legal advice. If you believe you are being treated unlawfully, speak to an employment attorney.