Don't worry at all, clots do not wander around within your circulatory system. The behavior of shifting pains is more likely a result of your anxiety/stress caused by your palpitations and your awareness of your dad's Afib. Physical fatigue can also give such pains.
You say you felt Afib!! Unless you have gone thru a few bouts of Afib its difficult to just feel Afib.... You need to have EKG done, some doctor diagnosing it as Afib etc etc
Probably what you had while biking were palpitations (they can mimic Afib).
Let me reassure you if you had a few transient (short duratuon- few or several seconds) bouts of palps you need not worry , they come and go. But if you have them quite often , a visit to your doctor will help.
You are young and fit, in all probability you and your heart are in good health.
I believe there are blood tests which can detect these things and clot busting drugs can be administered if a clot is found. However, I doubt if a clot is moving around the way you describe. Within just a few seconds of breaking free, they lodge somewhere and usually block an artery causing a lot of discomfort. You need to picture your circulatory system differently because the way you are thinking is not the way it works.
All your arteries have blood flowing in the same direction, so a clot cannot go backwards and take a different route. All arteries feed into smaller arteries called arterioles. These in turn feed into capillaries which are thinner than hair. So, a clot would have lodged somewhere well before now. A clot would have to be microscopic to pass through capillaries and enter the veins. So, the clot travelling to different parts of the body, blocking one minute, then moving again, is highly unlikely.