Medicals
If it helps - we don't usually send letters of offer for employment until your medical has been completed. If you have a security clearance still in progress it's very likely that the medical will not been sent out until after that has been completed and we've a ground training school scheduled.
I wouldn't be concerned that a training class has been cancelled - courses are cancelled and rescheduled all the time - it's a very dynamic environment so we have to shuffle things around to suit the business.
Just bide your time - you'll hear soon enough.