The 29-year-old became the first bowler to be banned for 12 months for an illegal bowling action and his appeal against the ban was also turned down by ICC's Bowling Review Group in Dubai last week.
"I am disappointed. I am not sure what the future holds," Ahmed told AFP on Tuesday from his hometown of Khanewal.
Ahmed was banned after tests on his bowling action proved he exceeded the prescribed limit of 15 degrees for a bent arm on the delivery stride.
He underwent remedial measures on his action supervised by former Pakistan seamer Sarfaraz Nawaz, but the ICC's review group upheld the suspension.
The review group included former Indian paceman Javagal Srinath and Sri Lankan batsman Roshan Mahanama.
"I will take advice from the Pakistan Cricket Board (PCB) and my captain Inzamam-ul Haq before deciding on what to do," said Ahmed.
Only one bowler in Test cricket's 130-year history has quit the game over an illegal bowling action.
Australian left-arm seam bowler Ian Meckiff was no-balled four times in one over against South Africa in 1963-64 and left the game soon after.
Ahmed, who has 51 wickets from 10 Tests, was banned after being reported during the first Test against England in Multan in November last year.