Do you think a combined income of 134k a year is enough for a family of 6?

We currently have three kids that are 6 & under. My husband & I are debating on if we should start trying for our fourth and last baby. Our hearts want another baby, but our finances aren’t so sure. We’re both in our late 20s. Our combined income is about 134k a year. I currently work 24hrs a week from home & my husband works full time. If we have another baby I won’t be able to go back to work full time for another 5 years. We’re surviving & thriving but another baby would put somewhat of a strain on our budget until he/she is old enough for school. We are so torn. If we decide not to expand our family my husband is going for a vasectomy.