My wife is pregnant and we are far from ready?

My wife is 24 and I am 23 we have 2 kids a boy (3) and a girl (1 1/2). We recently were renting about 4 months ago and got evicted and were pretty much forced to move into my parents house since I had also been fired from my job at wal mart. Yesterday she got a blood pregnancy test done and found out that shes pregnant. I had planed to get a vasectomy but she got very pissed at the idea of me wanting to get one because she wanted more kids. I my self thought a third child would be nice but far from now. And she refused to take the pill also. Anyways I have pretty much been worried all day and breaking down. I wouldn't plan on abortion either, I want my marriage to last and I can never forget the feeling the first time I held my son and daughter. I have no clue how to handle this.