I agree with what bronzeowl said, and I also think alot of it depends on the motivation behind getting the tattoo. If you can think of why you would want it (anything from it having a deep personal meaning to you, to just thinking it would look cool), then it should be fine. If you don't know why, maybe it's some sort of hidden SI urge. That's just my opinion though. I know there's alot of concern and confusion surrounding past/current SI and tattoos, and I think alot of it depends the combination of the person, the reason for the tattoo, and even the reasons they did/do SI. So, and I know this is the least helpful line ever, but it depends on you. You know the reasons behind it, you know how you feel. (I would hope so, anyway)

I've considered getting tattoos before, and don't think it would have any connection to SI for me personally. (The only reason I haven't is I don't know what to get, lol)

One last thing though, maybe avoid getting a tattoo when feeling very depressed/anxious/whatever led you to SI in the past, as that may increase the chance of creating a connection between the two. Just a theory.