What Causes Mild Back Pain While Swallowing?

Hi doctor,i have swallow 3tab of supplement at the same time,during swallowing i feel like 2tab have get into esophagus n one more is so difficult to be swallow like stuck in the throat,will it get down to the respiratory tract,as after few second i m trying push it down v water n saliva but i can feel a mild back pain,i m so scared abt it??