Hi. I'm 28 , I have doing sex 4 days before period and was recently supposed to get my period and it never came. Instead, I had a clear, odorless discharge which felt like my period. I took a pregnancy test when I first missed my period and it was negative, and I recently took another, and it still is negative. What could it be? Side note: I just started taking iron supplements, I am not on any pills or antibiotics.