I think i might have medial meniscus but im not sure can i still run on my knee?

It's not likely that you have a meniscus injury - braces don't have any effect on that type of injury. It's more likely that you have runner's knee, which can usually be fixed by proper exercising and stretching. Straight leg raises are one of the best exercises. There's good advice at the link - scroll to the links on knee pain.