Salary?

My fiancé salary has been bumped up and we now make 50,000 a year ( which I am happy about) but he now wants to try for baby #2 and as much as I want to, I'm afraid that 50,000 won't be enough fora family of 4.  In 4 years this position he has the salary will increase again to 100,000 and I definitely won't be nervous then.  But  I don't know if I wanna wait 4 years to start trying for  baby #2