dude,
the only time when you need nolvadex is when you get gyno, otherwise its not necessary. Like you said gyno is associated with dbol and other AASs, but gyno also depend on the individual, some are more sensitive than others.
So, if gyno does occur, take 20-40mg nolvadex/ED until gyno goes away or when gyno symptoms subside. Another point, you can take anti-e's like proviron added to your cycle to lower e levels, this will reduce your chances of getting gyno.
peace