Late bloomers do happen.......
A funny story...... I had a GF that was a conutry girl, she knew how to tell the boy kitties from the girl kitties..... She had this GIRL kitty for several years. She thought she was just lucky not to have any babies, as GIRL kitty was an indoor/outdoor kitty.....One day she was petting GIRL ( yes thats her name ) and she noticed that GIRL kitty had some big cuckle burrs ( it's a country thang... for u big city ppl, they are like HUGE grass ( or sand) burrs , aka... stickers) Well, she knew it was gonna pull the hair soemthing fierce, since GIRL kitty had such long, fluffy fur. So she grabbed hold of those burrs and gave a MIGHTY YANK ( thats Texan for PULLED)...... At that moment, she relized WHY there had been NO babies... GIRL was a BOY !!!!! GIRL did not appreciate things being PULLED !!!! hehehehe... we have never let her live it down.....
without looking or " feeling " I dont know of a way to know for sure....