I've covered the difference between primary and secondary sources in previous posts and told you that you should always strive to use a primary source rather than someone else's reporting of that source material. Obviously, an original interview that you conduct is a primary source. Don't overlook that fact if you later write on a similar topic. You can cite the expert you interviewed with a link back to that interview as a primary source for future articles.
This is an exception to the rule. Ordinarily, I think linking back to one of your articles as a source of factual information for a news report is not a good idea if the information you're citing was originally drawn from another source. In other words, many articles (especially news articles) are themselves secondary or even tertiary sources.
If your previous article said, "The FBI, on their website, are asking for the public's aid in locating Whitey Bolger." That's a secondary source with the FBI website being the primary source. If you wrote "ABC News reported that the FBI Director asked for the public's help..." Your article becomes a tertiary source, ABC News is the secondary source for the primary source which was the FBI Director himself. These kinds of chain references where the reader who wishes to check your source has to go through several links to get to the source are damaging to the writer's credibility, in my opinion, and should be avoided.
However, articles in which you personally conducted the interview and are bearing witness to what the relevent source said to you, are fair primary source references. There is no extra link in the chain for the reader to chase down because you've done the original investigation and reporting and these articles can credibly be used as primary source references for future articles.
Note that this is for news source references. If you include links to other articles you've written as additional background material, further reading, related topics, or also of interest pieces, that's a separate thing altogether and I don't take issue with that at all.