Keggin29,

Thanks for your question. 

At your age, cardiac causes for your pain are certainly unlikely, but the risk of developing blood clots rises significantly with the use of oral contraceptives. 

I suggest you make an appointment with your primary care physician as soon as possible.  It's been a month since this pain began, and you have more concern with the loss of your friend.  Your doctor will ask more questions, examine you, and possibly perform further studies to be sure that all is in order.  Be sure to mention to him/her that you are taking oral contraceptive medication. 

Assuming all is well, the peace of mind will be worth the visit. 

Best wishes.

Martin Cane, M.D.