Ok here it is my best friend who I have known for 18 years at least ( since we were 2) has not had her period in 4 months but every time she takes a pregnancy test it comes up negative.. how can that be.. I mean she is a little on the heavy side and I am really concerned.. I try and try to make her go to the doctors but she refuses saying it costs too much and junk. I have been trying to get her to see at least a clinic or something, what do you think is wrong with her and how can I change her mind about the doctors?? HELP :(