Need important question answered

Brittany

Long story short was having sex not even in no exotic position just missionary and we were getting into it when all of the sudden my chest cramped up on my left so bad i had to keep yelling stop at him it lasted for maybe 2-3 minutes then i got a headache and could still feel like pressure in that area in my chest I DONT KNOW WHAT HAPPENED or what to do and would really like some answers as it was painful and scary never happen to me before or anything even close