Don't count your chickens before they hatch
In Zulu Ungazibali izinkukhu zakho zingakaqala ukuzalwa.
This proverb is a direct equivalent, warning against counting on something before it's certain.
Example
"Wayesevele egubha, kodwa ngathi, 'Ungazibali izinkukhu zakho zingakaqala ukuzalwa.'"
