If you’ve ever been left wondering whether a work incident constituted illegal discrimination, you are certainly not alone. Federal and state laws make it very clear that employers and potential employers cannot discriminate based a person’s race, gender, age, disability or other protected status.

That being said, proving that an employer’s actions were discriminatory can be difficult. As a matter of course, companies often try to avoid saying any more than necessary when it comes to a work-related decision like hiring, firing, failing to hire and disciplining employees. This gives them legal cover if someone later tries to pursue a discrimination claim.

A good example is pregnancy discrimination, which is an all-too-common problem. Many women have experienced a demotion, layoff or allegedly performance-related firing after they disclosed their pregnancies. While the timing is suspicious, it is usually not enough evidence to prove discrimination.

In a recent New York Times advice column, a reader wrote about her experiences applying for a great new job. The employer seemed very interested, but she had not yet been offered the job. As a courtesy, she disclosed her pregnancy. A short time later, she was told that she didn’t get the job because of her inability to relocate. She may never know whether that was the real reason or not.

There’s no “perfect time” to disclose a pregnancy to a potential or current employer. It needs to be a personal decision based on the unique situation. In the case mentioned above, the woman could have waited until after a job offer had been made (or not made) to mention her pregnancy. If the offer had been rescinded after learning of the woman’s pregnancy, the case for discrimination would likely have been much stronger.

Proving employment discrimination is not always easy, but that shouldn’t deter you from seeking justice. An experienced employment law attorney can carefully examine the details of your complaint to better help you assess your legal rights and options.