Well, there isn’t a right answer here. I think that if you can do it with impunity, there is nothing to lose and much to gain by discussing things with an attorney. Especially since it’s not hard to find a family law attorney who offers free consultations.
A divorce is a major life change, and it only makes sense to discuss your case with a qualified professional before moving forward. An attorney can help you figure out how to prepare, what to expect, how you should proceed after informing your partner, and much more.
The only real reason not to talk to an attorney first is if you fear it’ll make things difficult with your spouse. In that case, it might be better to explain that you want a divorce and then go see an attorney the next day. But in general, it is best to do it sooner rather than later. Especially if there are children involved.