If that's the first time of using the machine/ doing a blood test, I would probably do a few more tests to check the results. Blood glucose monitors can be quite temperamental and have their own particular foibles as to how they want to be fed the blood -you have to let the strip suck up the blood in one gulp rather then smear it on or drip feed it. If you don't do it the way the machine likes it, your results might not be accurate.
A reading of 1.5 is really very low and I wouldn't expect that someone just on oral meds would get that low. If someone were to be that low they would be feeling it, a lot. That's why I think there was probably an error with that result.