I am having vertigo the past two days, mostly when i get up from bed or lay down, and it last for about 20 seconds. i know i had an intense vertigo episode years back for a week straight. had head mri/ ct scan for unrelated problem. am i to worry?

You probably have benign positional vertigo which is often a recurrent problem. Nothing to worry but sooner or later you should exercise to overcome it. When exercising by turning your head in all directions everyday, vertigo may recur at times but you will get used to it as time goes on, not much different from overcoming the seasickness in the initial weeks of navy or air force's training.