The 2926A get attached to 2926 at Ambala Cantt(UMB). The total journey time between Chandigarh & Ambala is approximate 1.5 Hrs. If you want to travel in 2A then book from UMB.
Ambala is very well connected to Chandigarh by road. Bus service & Taxi service is easily avoidable from Chandigarh Sector 22 ISBT.