Help!!!!!!

Sooo let me start off tell you guys that my period is a week late it was support come on the 20th of December and end the 25th... I had sex the 10th-11th of December how ever according to the app those where not my fertile days. And of corse my boyfriend cums inside me multiple times... well yesterday night my cramps got a little more intense as if my period was coming on and I felt a lil wet down there so I check and there was a little blood like spotting and I figured ok my period is coming on so I’m like cool... well I go back to check and it’s still a lil blood on the tissue but it’s less and less blood... then I wake up at 5am to use the bathroom and there is not one speck of blood on the tissue😕... I took a pregnancy test earlier this week and it was negative so I’m confused on what’s going on... I need some advice or if this happened to some of you guys comment please

UPDATE::: TMI!!!! I wipped myself and there was a little pink color on the tissue again 🤦🏾‍♀️ but no period