I just had my first session with a provider. From the moment she stepped out of the cab she looked a little "mannish" to me. Now don't get me wrong, I'm all for gender fluidity and live-and-let live, but is it possible she lied and is really a he? I found her on P411 - no mention of her being TS. But her voice was quite low. Her tits looked fake and felt hard. Yet her ads on P411 and Eros said her boobs were unenhanced. Reviewers raved about her boobs and how nice they looked.

the question you have to answer for yourself is:  So what?

During my first year in the hobby, back in the '90s, I called an agency and asked for a slender blonde. I got a not-slender blonde who was almost as tall as me and had big hands. Her voice was kind of rough, too, possibly from smoking. She told me that FS wasn't possible because it was that time of month, and offered me a CBJ. Partway through the BJ, I suddenly started to suspect that she was a dude, and began to wilt. Then I hyperventilated a bit and pulled out, and told "her" that I came.

There was a case not long ago where a delisted provider post op TS provider from here on TER was advertising as a "genetic girl" (fuck, I hate PC terms like that) on P 411, Once it was brought to Gina's attention and it was "proven" that she was a post op TS, Gina gave her a choice to either advertise honestly or be barred. This providers profile came down almost immediately afterwards so I can only assume Gina gave her the boot.

No, that's not all that counts.

There was a HUUUUGE scandal a few months ago about a post op who did have "post op trans" on her profile. She was passing herself off as a GG (born a girl). Enough guys felt things just weren't quite the same and must have written Admin. Things got really nasty after that. I can't name her because she was delisted from TER for retaliating against some people both guys and a few ladies here.

Typo, Steph. You said, "who did have "post op trans" on her profile."
You meant, "who did NOT..."

in my first sentence.

Not necessarily his first ever session.

If you had a good time AND are still curious, schedule another session. If you're uncomfortable asking outright ("Excuse me, but do you, by some chance, have a Y chromosome?") sneak a DNA sample and send it in for analysis.  

Was she a body builder? Even a former body builder who might have been "juicing" or taking hormones.  
Also, chronic pain patients who are on long-term narcotics for pain control may have to take testosterone as part of hormone replacement because some pain meds wipe out the body's natural ability to produce testosterone on its own. The same holds true for long-time heroin users or other Opioid users.
 

Right, first time with that provider

He tried to white list a lot of us I think to hurt us.    Not supposed to be on ter any more but could be using a different name.     Ter took us off of his white list at our request.     I had never met him but that's what the reviewers said.   Most TS's identify as one which is what they should do.