I had a ct scan two weeks ago which was normal. does that lessen my chance if having a stroke ?

Not really: It lessens the liklihood of a certain type of stroke called a hemorrhagic stroke caused by ruptured anerysms.

No: Chance is significantly higher if your BP and glucose are not controlled. Ct only tells current anatomy, it doesn't predict the future.

CT scan: Having a normal ct scan is good but does not affect the risk of stroke, stroke risk are more based on medical problems such as hypertension, high cholesterol among other problems.