Torn condoms do happen from time to time.

You need to see a doctor and get tested.

You are in no position to find out for sure if she does or not.

At least know that the odds favor you.

If you don't think you can trust her, why did you see her?  A quality, well-reviewed provider has just as much, or maybe more, to lose as you do.  She has no more assurance that you are clean than you do of her, just because you say you are.  

If you get checked and are STD free, then she probably is too.  But, I would not rely on a single test.  Have it repeated after a time to be sure. However, short of asking her if she is clean, I don't know any other way.  I think most providers, if they have any class, might be mildly insulted if you ask them directly.  Under the circumstance you described, asking might be more acceptable, as long as you don't mind her asking the same question of you.

In any case, both of you should get tested and let the other know the results, not just once but at least twice.

Swim

she may be asking the same questions about you, as well. She's the one whose risk of catching something from this incident is many times greater, so I think being honest about your own status would be appreciated and maybe reciprocated.

I was seeing my regular provider, she uses a hat every time with everyone. In the middle of the session, it started feeling really good, then I looked down, and the condom was inside her vagina. At first, I didn't know where it was, then she pulled it out of her vagina. We just put on a new hat and continued.

Now, she uses many safety measures with all of her clients, and she appeared to take care of herself. That doesn't exclude her from any STD's, and I didn't ask. I did however got tested two months after seeing her, and so far, I have nothing. That doesn't exclude me from future STD's if I am not careful. I am now more weary of BBBJ's than ever, so its better to always wear a hat even with a BJ.

What I can recommend is finding a condom that fits. My provider had some ultra thin condoms, and that is a reason why it came off. I never had a good experience with ultra thin condoms because it is just too small for me, and it doesn't help when the pussy is tight. Also, don't wear a Magnum if you can't fit it, otherwise, it will come off. Find a well name brand condom that fits you. I now always bring Magnums with me because it fits me perfectly. If you know a condom is too tight on your John when it has no room to breath, find another one. You know a condom is too big if it is too loose, find another. Also, having KY losen the friction of penetration and decreases the chances of condoms coming off. Hope my experience was helpful.

Certain STD have no symptoms so the provider may not even know they are carriers.  HIV doesn't even show up as positive during testing until several weeks after exposure but can be infectious within days.