Unfortunately, the chances are quite high!

Even WITHOUT a cold sore actually present on his lip, he can still spread it to you if he goes down on you. This is from 'asymptomatic viral shedding'. This is why herpes can be spread even if someone does not have a sore on them.

I have genital herpes, but not from a mouth cold sore. I take daily suppressive therapy, that keeps outbreaks away and prevents spreading it.

IF you do not wish for him to spread it to you, he either needs to take daily suppressive therapy, or needs to use a dental dam.

the chances are high like carifary aid

if you knew he had it then why did you allow him to go down on you?

I would get tested for oral and genital herpes. Both of you should be tested so you can see what each other has. Then you can take the necessary precautions and if needed preventative therapy. As the other posters stated, there is a high chance you could have gotten genital herpes.

You as a couple need to sit down and talk about what you would like to do. I have herpes also and I have had 2 relationships where I have had to do this. Its hard but you have to do it for yourself and him. There is no need to get herpes if you can stop it. Best wishes