Recently my stomach has been feeling kind of bloated and I've been really gassy. Gas is released when I massage my belly, and it smells awful! Today I noticed a kind of dark line going from my belly button down, and a dark patch of skin (not a mole) under my right breast. What is this? I have had the contraceptive implant for 3 months now, with periods in between, so I'm pretty sure it isn't pregnancy, as my friend has suggested. What do you think?