You should sue

It sound like you are an exempt employee.
1. Sexsual harrasment. Civil charge does not require solid evidence. You only need to win the judge and jury's heart.
2. If you are pregnant at the time of being fired, you can sue the company for discrmination.
3. You can sue the company for pressing you to work extra hours without pay.
Consult an employment lawyer. Try searching www.bbb.org