Please submit a request letter for a Maternity leave with your Employer with proof of maternity (Doctor certificate) directly in advance one month before proceeding on Maternity leave. Don't ask questions " whether I am eligible for maternity leave" with your employer.
Maternity Benefit is applicable to all establishments employing 10 or more employees.
As per Maternity Benefit (Amendment) Act, 2017 you can avail 26 weeks (182 days) Maternity leave with wages.
Your categorical statement that the establishment is a manufacturing Company shows that it must be a factory under the Factories Act,1948 and therefore the Maternity Benefit Act,1961 applies to it automatically irrespective of the no of employees employed therein.
As you said openly, since it is a small size establishment having no specific HR policy, if any on maternity leave to employees among them you happen to be the only female triggers the fear in your mind. Such a fear might be unfounded or real depending on your organizational culture.
The discharge or dismissal of a woman by the employer during any time of her pregnancy is expilcitly prohibited u/s 12(2)(a) of the Maternity Benefit Act,1961.
The maternity benefit contemplated u/s 5 of the Act is 26 weeks of leave with wages. Keeping the expected day of delivery as certified by a registered medical practitioner as the point of reference, the employee can take 8 weeks of leave prior to delivery and the remaining weeks after delivery.
THEREFORE, if you officially inform your employer about the fact of your pregnancy now, they cannot resort to any legal action resulting in your exit.
If you are skeptical about the attitude of employer, you may choose to intimate the fact just before your proposed maternity leave.