There has been a lot of speculation as to why Elizabeth I never married, but I have a hard time believing the AIS explanation.
First of all, medical records, in the modern sense, weren't available in the sixteenth century. Even if they were, medical science at the time probably wouldn't have known about Androgen Insensitivity Syndrome. Even circulation of the blood was unknown among European doctors at that time, so I doubt that they would have known of something such as the condition you describe.
Now, it is known that Elizabeth's half-sister, Mary I, suffered from a condition that caused irregular and scanty menses, and I believe that Elizabeth's cycles were also somewhat erratic. There really wasn't much of a sense of privacy in the era under discussion, especially among royalty, so the menstrual cycles of a queen were a matter of scrutiny.
Whether Elizabeth and Robert Dudley ever consummated their passion physically is also open to debate. Again, it isn't likely that they were able to carry on a clandestine affair because of the aforementioned lack of privacy as we have use of the term. Someone, somewhere along the line, would likely have leaked this information and it would have created a major scandal.
Even, or perhaps especially, queens were subject to the societal double standard that allowed men free range in matters of sex and expected women to maintain their chastity.
