This might seem like a stupid question but any feedback to ease my mind would be nice!

So I last had sex around December 18th I believe and we use protection every time birth control and condoms. I started my period last week (normal) but when it ended I started noticing that my stomach lower abdomen was feeling tight so I took two preg tests and both came back negative (I took one last week after period then one this week.) When i’m wiping now i’m seeing a little light brown discharge or

something. What do u guys think? Thanks babes