Is it me (just luck) or the confirmations are really getting faster ? last time I got transaction confirmed in eight minutes and now in 2 minutes only while I was getting them in like 15-20 minutes.
It's just you, and it does sounds like luck.
But to talk in terms of minutes to comfirm, without reference to how many blocks were mined in that time is ambiguous.
Were you in the first mined block to come along, or the tenth?
If you were in the tenth block (even though it only took 2 minutes) you may not have been as lucky as you thought. But you probably feel lucky
If you were in the first block (even if it took an hour) you may have been lucky. But you probably wont feel lucky.
If you always got into the first mined block to come along, you will still see these 2 minute - 1 hour+ variations.
Even if hash power stays exactly constant. (or even if it increases)
It is impossible to say blocks are getting faster because your last transaction was faster than the previous.
(no evidence can be gleamed either way)
The only luck we can say you had was that your own personal transaction comfirmation times was in decreasing sequence.
And the thing with luck, it will change.
Luck says your next transaction will be slower than 2 minutes.