FALSE NEGATIVE

Hello mommies! Meron ba ditong napreggy na ganito ang situation? 2 weeks delayed na at first time nangyare sa akin to. 30 years old and TTC NagPT aq 3days before period pero negative. Inulit ko on the day of my period pero negative parin. On the day of my period may lumabas na watery brown discharge. Akala ko magkakaperiod na ako. 2 weeks after wala parin ako period until now. Hindi pa aq nagppregnancy test kase feeling ko baka umasa na naman ako. Meron ba ditong same situation? na negative before and during period pero after a week or 2 nagpositive na ang PT? Thank you so much.