Recently Gmail got a new look, since then I forget about clearing spam messages because by default it’s hidden in “More” menu on left-side and appears only if you expand it (the case with me in all my Gmail accounts). I came to know this today when I expanded More menu to see Spam label with count of 11 unread spam messages, when I checked these- there were some important ones, so like this I may have missed some emails which are actually not spam, so now I’ve set Spam label to always show in the labels list, here is how.
Set Gmail to always show the spam label in the labels list
Expand “More” menu and click on Manage labels or visit this link directly in your browser after signed into Gmail), now for the Spam system label click the show link displayed under “show in label” list which turns to bold now. Check Spam label now, appears below the Drafts label. You can also do this by moving the spam label up, just drag and drop spam label above More menu.