The 25-year-old singer is expecting a baby with model Caterina Lopez and he is worried he won't be there to welcome his child into the world because the band are on tour later this year.
However, JJ hopes 'The X Factor' boss Simon Cowell will come to his aid after his band found fame on the UK version of the reality show.
He told OK! Magazine: ''I'll do everything I can to get there.
''I heard one of the sound guys at 'Britain's Got Talent' was having a baby a few years back so when his girlfriend went into labour, Simon Cowell loaned his private jet so he could be there at the birth. So, Simon...''
While JJ is hopeful for Simon's help, he believes that, in reality, Union J's tour manager Martin will get an emergency call and JJ will rush to the hospital.
He added: ''We'll have the baby and then he'll [Martin] have a cigar waiting outside. It's a celebration, isn't it?''
JJ also revealed that fans have already been sending him expensive baby gifts.
He told Britain's OK! magazine: ''They've been so sweet. I was nervous young fans might not get it, but they've been amazing.
''They even send gifts, expensive stuff such as clothes from The White Company, a Maclaren bag, teddy bears.
''I'm excited, I'm not even worried at the moment. I suppose it's going to hit me when the baby's born.''