i read your question and understand your concern
i would like to ask that
* your age
* marital status
* any kids
* family h/o breast cancer/any other cancer
* which type of chest problem you were having in past?
* which type of pain is that
* is that lump itself is painful?
* is it hard fixed or move able?
*do you feeling pain in lump on pressure/touching?
* any discharge from that lump/or nipple of the affected breast
* have you examine your other breast is there any other lump?
* any lymph
node swelling in both the axilla?
so i would suggest to go for one USG breast first and then go for Mammography
and other tests and meet your gynecologist for further advise and treatment accordingly
i hope my answer will satisfy you
good luck & tc