पूजा सुपरफास्ट - हर रोज़ चलूँ मैं तेरे साथ मंज़िल मंज़िल - by Shubham Yadav

I have two SL tickets to travel from Mumbai to Bhopal HBJ on 30 Apr 15
First is in 12137 Punjab Mail - Currently WL 115. Its departure time 8 PM from Dadar Suits me the most
Second I have in 01713 LTT HBJ Special - RAC 33 right now. Departs at 5 PM from TNA. Will have to take half day leave from office.
Query...
more...

is - Should I right away cancel the 12137 ticket as there are little chances of CNF due to high WL, or shud I wait for few days and cancel 01713 ticket when 12137 ticket approaches CNF?
Want to lose minimum possible money as cancellation charges.