I think there's an issue here with confusing three sets of figures.
HbA1C is now reported according the the IFCC standard, which is in
mmol/mol. This is the number that typically runs from about 30ish upwards. A 'good' A1C by this standard will be 48 or lower, typically.
Previously, HbA1C was reported according the the DCCT standard, which is expressed as a percentage. Most people who've had diabetes for a long time will be used to thinking of their A1C in these terms. A 'good' A1C by this standard will be 6.5% or lower, typically.
However, individual blood sugar tests (as in, what your blood sugar is doing right now) are measured in
mmol/l (in the UK, anyway). This is NOT the same as the IFCC standard.
Where confusion occurs is because the DCCT method of reporting HbA1C gives numbers that are broadly similar to individual blood sugar tests...but not exactly. So it's very easy to talk about an individual blood sugar test being '6.5', but also to talk about an A1C being '6.5' - but these are NOT the same thing.
A converter between DCCT and IFCC units is available here -
http://www.diabetes.co.uk/hba1c-units-converter.html
Just to keep things even more confusing, you can also do a conversion between A1C and estimated average glucose (eAG) ie. you can find out what your individual blood sugar readings are generally like, based on your A1C.
A convertor is here:
http://professional.diabetes.org/diapro/glucose_calc
The confusion doesn't end there, as other countries also use an entirely different system again for measuring individual blood sugar readings (mg/dl) and other countries will also use eAG instead of A1C!
To cut a very, very long story short though, if your blood sugar reading of 17.4 was in mmol/l (ie. an individual reading), if we assume your average blood glucose was this figure, using the second calculator, this translates to a DCCT A1C of 12.6%, which then converts (using the first convertor) to an IFCC A1C of 114.
Phew!
However, after all of that, there are really only a couple of things you need to know.
You should aim for all your individual readings to be below 8.5mmol/l
You should aim for an A1C of below 48
You should not expect to achieve these readings when you've only been recently diagnosed and you should not beat yourself up if you don't make them. The important thing is to be heading in the right direction, which you certainly are.