Shortness of breath and faster heartbeat only in 3 weeks pregnancy. should i be worried?

No: This is very common. It is due to the increase in your progesterone level. But f it becomes severe (and you have chest discomfort or cough or heart rate over 100 at rest or fever), get seen right away.

Contact OB MD: You need to contact your treating OB MD who can put your symptoms into the proper context knowing your history and give you an accurate answer.