why?

hi im 18 years old i been with muh husband almost two years i lived with him for 5 months the last three months i lived with him were livin hell!!!he had told me he couldnt have kids i believed him n didnt use protection...for those three or four months i didnt get pregnant untill i was goin back home to california never expected i end up pregnant...three weeks had past n i didnt get my period so i was a little worry i felt sick almost all the time n seem like i was eatin more...i got scare n bought a pregnancy test i had got two for incase of anything i took both n came out positive i couldnt believe it i didnt know wat to do or wat to say to my husband..i called him n he never picked up so i called him the next day n told him i was pregnant...all he said was "i have 97% of my sperm dead how can you be pregnant?" i said "i dont kno but i just am"..do i have to worry bout him believing me wat should i do???