Federal law allows you to take time away from work when you have a family or personal emergency situation under the Family and Medical Leave Act. The FMLA safeguards your job for you, meaning your employer cannot fire you while you are out under FMLA.
The Department of Labor explains that after ensuring you are eligible to take FMLA leave, you will need to formally apply for the program.
You cannot call off and tell your employer you are taking time off under FMLA. You need to provide adequate notice of at least 30 days in situations where you are aware you will need to take time off. For example, if you are having a baby or your husband is getting surgery and you will need to take care of him after, then you know ahead of time you need to take leave.
If you cannot give notice 30 days in advance, you need to do it as soon as possible. You can use the regular methods your employer requires for calling off work to do this.
You will need to provide your employer with enough information to classify the leave under FMLA. You do not have to specifically request FMLA leave during your initial request, but it must be clear to your employer that you wish to use this type of leave. If you need more time off under FMLA, then you must state it is FMLA leave. If you fail to ensure your employer knows your leave is under FMLA, you may not receive coverage.
It is also important that you make sure your employer must offer FMLA and that you qualify as an employee.