Forgetful....or is something more sinister going on?

I am concerned, with good reason, about myself and my future. On my mother's side of the family each and everyone of them from Grandmother down have suffered from Alzheimers. My mother often mixes things up and repeats herself time and again but she still seems to be going strong, thankfully. So I wonder if I should be worried about little things that happen to me, like for instance I have gotten into my car before now, started driving only to have a complete blank mind as to the route I should take to get into town (we've only lived here for 30 odd years!). So how do I determine whether I'm just forgetful due to age (a very young, sprightly 55yrs!) is it normal to forget words in the middle of a sentance? Names of people, places, things, etc? Whether or not 've seen a particular film (not all the time but just sometimes I can sit thru half a film only to find I've seen it already). And what about where I've put something when I want to keep it safe? I always wonder if I should make a note of the safe place in a file but decide against that as it would no longer be a 'safe' place and then spend days (and I'm deadly serious here) looking for the damned thing whatever it is which I invariably find when I'm actually searching for something else!!! And we'd best not start on the going upstairs for something only to remember it once I'm back downstairs again!!!
So, is this the beginning of Alzheimers? Mother decided to ask the GP if she could be tested for it and was told there was no test and not to worry (at least this is what she thinks the GP said to her, but can't quite remember!!!). On my father's side I have an aunt who is 96 yrs old and she has the most amazing mind, she is all there and hardly forgets anything, I'm hoping I will take after her and not my dear dad or his mother who both died in their early 60's of massive brain haemorrhages.
I am determined, dear reader, to live my life to the full, have lots of fun, be daring, outrageous and maybe sometimes a little disgraceful at least when the time comes for me to bow out of this existence nobody can say I haven't lived. I have taken on so many roles in this life and I have laughed and loved through all of them, but the details of these roles are saved for another blog when I have more time, until then my dear reader I beg your patience..........