What is your goal? Are you paying child support and want that support obligation terminated? Is the mother pursuing a paternity case and child support? Is there any court order mandating you do anything with regard to the kids? Do you want to cut off the possibility they will pursue a claim on your estate after you die? Do you want to pursue your own case to establish paternity and seek visitation and other rights with respect to the kids (bearing in mind that course of action will likely also result in a child support obligation? If it's any one of those things, then yes, see an attorney first. There are specific requirements for a genetic test result to be admissible in court. It will be pointless and a waste of your money to get a test done that may not meet those standards. Also, see the attorney ASAP as there are time limits for these kinds of legal actions.
If, on the other hand, you are simply curious about it, then don't bother getting a paternity test done on the sly. Bear in mind that doing that might constitute a crime if it turns out you are not the father. Why? Because if you aren't the father you don't have the right to subject the kids to medical tests, especially tests that are done without any medical purpose.
