My girlfriend has a lump on her breast which she refuses to get checked ??? ?

i dont no wat to do ... Im about a day short of puttin her in the car and dragging her ther !!! I found it when we were foolin around but as soon as i mentioned it she got all freaked out about it !!! And is now refusin to talk about it ... I have a feelin she knew it was ther tho like before i found it which worries me even more !!!