testing over the next couple of hours will give you the answer
take your last test as your baseline and if you have increased above a comfortable range for you ( we all are different in what is comfortable to us )
I would change
alternatively -- wait a bit longer -- set an alarm for 1AM or so -- test and change if above 14~15
the money side of things is irrelevant in my opinion
( if you do nothing but tape it up and are in DKA by tomorrow morning the NHS will spend a couple of thousand on you with ambulance , and time and treatment in A&E