so I took a pregnancy test this morning, and it was negative. which makes me sad, but for some reason my boobs are very very tender and hurt if I out even the slightest pressure on them. I've also gained some weight, I'm been eating for then I normally do, which is strange to me.. and my friends say I should go to the doctor and get a blood test done. but I'm not sure on what to do, especially if the test was negative. give me some advice please.