I need to find a birth certificate for the following:

Male Durbur
26 January 1898
Father: Frederick John Durbur
Mother: Bertha Prier
New Jersey

i am very confused because no ever heard of my great grandparents having a son AND what's funny is this date is exactly one month one day before my grandmother, Bertha Durbur was born!! I need to see proof this son was born and make sure the transcriber did not write down male, instead of female and put the right date and NOT 27 January 1899 which was my grandmother's birth date. Thank you.