Hey everyone I'm a mom of 2 under 2 , I was on birth control since January my periods were irregular , I recently…

Hey everyone I'm a mom of 2 under 2 , I was on birth control since January my periods were irregular , I recently stopped taking the birth control due to my period calender stating I'm 16 days late. And yes it's quite true , however I took a pregnancy test and it came up negative. Take note I was still on the birth control. I am not trying to conceive I just do not want to harm the fetus should I be pregnant. any advice or experience is welcome thank you!