Hi Simtree
If the doctor has put you on medication which can cause low blood glucose, he also has to provide you with the means to 'fingerprick test' your blood. Hence the way to tell for sure, is to test our blood.
I'm Type 1, so obviously need to inject insulin since my body no longer produces any, unlike the vast majority of T2s who still are able to produce more than enough, but instead their bodies can't use it as efficiently as they're supposed to. High BG feels totally different to low BG to most people so those that are liable to get them, quickly have to learn recognise that they are. Many of us carry a few jelly babies - about 3 of them is often enough to sort ourselves out. We have to test our blood again in 10-15 minutes to make sure the JBs have worked sufficiently.
What meds are you on, and where have you been told that you are likely to suffer low BG?