What happens if you get a woman pregnant then flew the country?

i think he should get aDNA test if its his then he can leave the country if he wants if its not he can live his life normally...what if he keeps this secret to himself he's never going to have a free conscious and the baby might not even be his... tell him the best thing to do is to find out for sure..rather than changing his whole life for something he is not even positive about!