How long after a cardiac ablation can a blood clot be detected?

Any time: There is no limit to the time after ablation when one can detect a clot. However the risk of clot formation relating to ablation can extend to one month.

Huh?: Ablations don't generally cause blood clots. If your ablation was complicated by a blood clot, it's probably being treated with an anticoagulant and the duration would be variable and depend on location and size. It is common to prescribe an anticoagulant for 3-4 weeks after ablation to prevent a clot from forming from the change in heart rhythm. This is prophylactic.

About 2 Months: We usually advise people remain on vigorous anticoag for 2 months. Most of the risk is in the first 1-2 weeks though.