I got my tattoo 9 years ago, but only after I had thought about it for 3 years. And I don't regret having it at all.
I wanted to make sure it wasn't just a passing fancy, and that I really did want it since it's
permanent!
Mine is on the back of my hip, below the underwear line. This way it can easily be hidden by clothing, and no one even knows I have one unless I tell them or show them.
It's actually kind of funny to see the reaction when I admit that I have one to people. Most people would never guess that about me because I'm pretty reserved (and a little geeky), so it's fun to reveal my "secret" wild side.
As for weight affecting it: it hasn't. I got the tattoo when I was at about my current weight (198). I've bounced up and down the scales for many years, ballooning up to 250, and back down. The tattoo hasn't been affected one bit.