My chest area has 1 pimple but there is alot of redness my dermo gave epiduo after that redness came can i use clear gel ?

you should expect at least 1 week of treatment and leave it gradually until using gel solution also avoid sun exposure until pimple ends scaring

You are right in stopping the Epiduo until the redness subsides. I am not sure what "clear gel" might be, but I would apply a light, plain moisturizer over the red areas after cleansing the area with a mild cleanser