You're very wise to do that. When my husband and I bought 8 years ago, we bought a house based on the one income scenario.
Two years later, I became very ill and had to quit work permanently. Had we bought what we could afford at the time, we would be out on the street. You never know.
We did the same thing, and while we've never had one income completely disappear, we have had our ups and downs with specific jobs.
Of course, we couldn't afford our house today, most likely, the way it has appreciated, but then, we don't have to buy it today.