I am experiencing bruising (quality: after trauma) about two weeks ago i got a hickey on my left boob ... & it was slightly black and blue now blk & blue is gone, can it leave behind a lump ?

No lump, color: There should not be a lump, but your skin may be discolored for months and only resolve very gradually. If you are bruising with minor trauma, you should see your doctor for an evaluation. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex.