Can vitamin k2 (mk7) cause blood clots? i took one dose and ever since have had chest pain/heaviness, palpitations and slight dizziness...been almost 72 hours?

This was likely an individual allergic reaction to some material (even a trace amount) in the product, not the vitamin K which is present in foods you eat. The natural vitamin K is a co-factor in the formation of the blood factors that allow you to clot normally. The exposure you cited is unlikely to have any effect on your clotting, or anything else. I would avoid that product in the future.