Tattoo?

So, I'm thinking of getting a tattoo. Probably on the back of my neck (just on the top vertebra, or one down), of a double triquetra (something like this except obviously without the pendanty bit), in plain black:

Preferably about 1.5cm each way, so not too big. Except that that design may be a bit complicated for that size, so maybe this instead:

But I'm not sure. I hestitate to do something so permanent, and I feel
that if I'm not 100% sure I shouldn't do it - but I keep deciding not
to, and then coming back to the idea. I don't want to get to 70 or so
and regret having it done, but I don't want to get to that age and
regret *not* having it done, either.

I'd like it to be somewhere where it would be visible or not, depending on my choice - back of my shoulder would also be a good place, but it would never be
seen since I never wear sleeveless tops. I had thought of up the top
of my neck, just below the hairline - I wear my hair quite short now -
but I'm a bit squeamish since that's a bit too close to my spinal
column for comfort. The traditional locations - hip, lower back,
ankle - wouldn't work well for me... I really think you have to have a
very good figure to be able to pull that off :-)

If they weren't so permanent, I wouldn't hesitate - if they lasted for
10 years or so, or lasted indefinitely but you could remove them at
will.

I just can't decide if it I should get it done or not! It's totally out of character for me... but that's kinda why I want to go for it ;-)