Bulma And Vegeta Doujishi On Dragonball Z How Did Vegeta And Bulma End Up Having A Baby?

On dragonball z how did vegeta and bulma end up having a baby? - bulma and vegeta doujishi

I only know that the vegetation was parked training on the equipment Bulma house, and I realized that I wanted Vegeta Bulma, but apparently did not like. So I was wondering if anyone knows what they have in common. because if Vegeta was the training of the androids in 3 years is available, never proved anything in three years.