Sarahgyn-
I read your post when it first appeared and I had to take a few days to weigh my response. Now that I've done so, here it is.
No, the only difference is not that you're female. The difference is that you claim to be a doctor, and as such, you should know better. I don't know how long you've been involved in the fetish, but if you read some of the threads on this forum, you will find that most of the females here don't get a particular thrill out of going for our annual exam.
Sure, we might find our doctor (male or female) attractive, we might even use the experience of the exam as part of a later masturbatory fantasy, we might use the experience to titillate our partner afterward. However, that doesn't mean that we want to have our doctors' fingers on us or in us for even a second longer than necessary.
The fact that you are inclined to do so says to me (and I think a few others here) that you have a lack of respect for the dignity of your patient. If I were a urologist (which would be my chosen specialty if I were an MD), I wouldn't dream of handling a man's genitals for longer than strictly necessary or "going deeper" during a DRE. It's very disconcerting to me that I, as a layperson, have a higher standard (albeit fictional) than you do as an MD.
If you are indeed an MD, all I can say is "shame on you", Doctor. You have indeed crossed the line.
LadyDoc