Yo...
I used to get these too bro.
Ok...Seems like you dont get em enough to test a theory.... But does it kind of sound like a click.... You said pop. But mine were somewhere between both. Esp apparent when walking....Each time my foot went down... They eventually went away. Go get an mri if your freaking out... Worth the peace of mind.
Oh my theory....Do they only do it while walking? If so, next time it happens.... Bite your jaw together hard to tense the muscles. I found this syopped it... But it sounded in my brain like you said... Kinda temple area....
Dont stress mate... Go see your doc and if you@re getting stressed or depressed about it.... Let him know and make him send you for a scan...Trust me, I know what worrying about health conditions can do to you. Get the all clear and youll forget all about it, itll soon stop then