VERY common in my parts lol.
In fact, it's probably the only term most people would use when describing it - the woman falls/fell pregnant.
Unless it was in times gone by, like my grandmother back in WW2 when she was mentioned in the local newspaper because her husband was a bigamist (this is a true story - I have the newspaper clipping somewhere), she was described as being "of a certain condition". She was of course pregnant.
Don't you love words?