Sick and tired...

I have been with my SO for over a year we have had our ups and downs like normal couples do but I am 14 weeks pregnant with our 1 child together and now he just snaps last night all of a sudden he don't want to get married or the baby I am totally lost hurt and pissed idk what to do....he has really hurt my heart this time to the point I just want to walk away but dont understand at all