1) Usually maternity leave only starts at birth, so a pregnant employee may be expected to work until the end of her pregnancy.
2) If you are ill or have complications beforehand (and need bedrest for instance) that usually is not considered maternity leave but normal sick leave (so what will apply is your employer's sick leave policy, or if there is none, Swiss labor law)
3) you are protected for 16 weeks after your pregnancy, meaning that you can not be laid off during or for 16 weeks after. That does not mean you are automatically entitled to 16 weeks of paid leave.
4) Unless your employer has a specific maternity leave policy or depending on the canton you are living in, again Swiss labor law will apply.
Perhaps things have changed since zee olden days of long long ago....

Not sure, you'll need to check your contract and labor law.