I used to find it awkward telling people I was a diabetic but then I realised how important it was for people I was likely to spend time with to know (especially work colleagues). I now find it quite easy to tell people and believe it helps others to know more about it as there's so much ignorance on the subject.
Yes definatly need to tell employers about it. I test in public/infront of anyone, even at the shop etc, i have no problem with people seeing that. Most of the time people are really interested in it, can be rather annoying having to explain it all though. My colleagues forever asking me questions :crazy: