Do porn stars catch stds during oral? or what?

I was wondering do they catch STDs if they don't use a condom?

Not all porn stars have STD's, in fact they get tested pretty regulary to make sure they dont so they won't pass it to other people.

If they have an STD then yes they could catch an STD. But like mandyloo said they get tested regularly.

Well,everyone says Oral without preotection leads you to a risk of catching STD,so do they catch it? if,it's ok for them,why not for me?

The only way you can get an STD is if the person you are with already has one. Blowjob do not equal STD's. Getting a blowjob from someone who already has one does though.
You are getting confused. I think you need to research that a little bit more.

Ok, first off you can only get an STD if the person you're with has one. If she doesn't have one then don't worry about it. Anybody...ANYBODY that has any kind of sexual contact with ANYBODY else is put at risk for an STD, even porn stars. However porn stars get tested for STD's regularly, you don't. And I would guess that the girls you're with also don't get tested. There are a lot of STD's that have no symptoms and there are some that you can see the symptoms (herpes).

Anytime you have sexual contact with someone you (meaning everybody in the world) are put at risk of catching an STD. The only way to be sure that you won't get one is by practicing abstinence. The second best thing is by using protection (condoms). But remember, everybody has a chance of catching an STD, even porn stars.

Any STD you can get downstairs, you can also get from oral - or GIVE with oral if the infection is around the givers mouth. Gonorrhea of the throat is an actual problem.

Porn stars only get tested for a few of the STD's. HPV (genital warts) is not tested for (indeed there is only a clinical test for it - the doc has to SEE an outbreak). Herpes is hard to test for.
Plus even if they are tested, they have a great number of partners more than everyone else.

Incidentally, in your age group, about 50% of all sexually active people have HPV. Mostly it is not a big deal. Gardasil vaccine will protect against many of the worst HPV strains. (NOTE: it won't CURE HPV, it only prevents you from getting four of the major strains.)

Practice Safe Sex, and
Good Luck!!