I am going to have a baby in March and I am the only employee for the company that I work for. What I wanted to know is if I am entitled to my six weeks off for maternity leave being that I am the only employee. My boss said to me that I would not be entitled to the six weeks that I should take the time needed and that the law says that he could hold my job or someone else could get it because he has less than 50 employees. By the time I have my baby it will be 1 year and 5 months that I have worked for him. What should I do cause I am really not sure.

Since your employer has less than 50 employees you are not eligible for FMLA no matter how long you have worked there, and NY does not have any state-mandated maternity (or other medical) leave. So no, there is no six week leave or any other length leave that you are guaranteed under the law and your employer is not required to hold your job for you.