Regular expression containing one word or another
You just missed an extra pair of brackets for the "OR" symbol. The following should do the trick:
([0-9]+)\s+((\bseconds\b)|(\bminutes\b))
Without those you were either matching a number followed by seconds OR just the word minutes
You can use a single group for seconds/minutes. The following expression may suit your needs:
([0-9]+)\s*(seconds|minutes)