English placement, should you still take it?

So I took ERW, because Mr. Pendleton told my classmate and I that if you pass ERW with I think a C or higher, you wouldn't need to take the placement test for English in college. He told us that this class, if you pass, will for guarantee you a English 1 class in college. I'm wondering if I should still take the English placement test still? The reason why I am questioning if I should take the placement exam or not, because I think that I will be struggling in the English 1 class in college. See I'm struggling in ERW, possibly going to get at least a B-. If I'm struggling in this class, I'm assuming that I possibly wouldn't have a chance in college's English 1 class.  So I'm wondering if I should just take a placement, if I can. Also, does anyone else struggle in this class or think they will struggle in their next English class in college?