Clomid works by blocking estrogen at the pituitary. The pituitary sees less estrogen, and makes more LH. More LH means that the Leydig cells in the testis make more testosterone.

Nolvadex is used mostly to stop gyno by binding with receptors in the breast tissue. So Nolvdex blocks estrogen in the breast tissue.

So this is brief but the reason why you Run Clomid and Nolvdex in your PCT is cause they attack two different areas. And both help increase your natural testosterone. By blocking estrogen at the breast tissue(nolvadex) or the pituitary (clomid)—which in turn helps your body kick in its natural test because both increase your LH

This is just a quick brief run down hope it helps—however, Google is your friend and so is this site.

So in turn--you want to take both.

I think you mean pct? not oct? and like fast said go into community and read read read