The case scenario described where if a small particle (a piece of wood in your case) were to get stuck on the lining of the ventricle and produce symptoms after 8 months (with perfect health in between) is fictional. The only way to rest your fears would be to have an ECHO done to assure your fears that there is no foreign body.
Your understanding of the mechanism of how blood is pumped through the heart is correct.
If there is in fact a piece of wood floating in your ventricle, no it would not hit and lodge itself in the wall of the ventricle because only a piece of wood of significant size could inflict that type of piercing trauma.
Hope this helps