Implantation bleeding or weird spotting?

We had protected sex last sep 3, then around 9pm of sept 11 may bleeding ako. I considered it light kasi almost 3/4 ng panty liner is puno, pero i dont think it is spotting, iba pa yung na wipe ko na nasa tissue. The next morning may nawipe akong blood, thick yung blood parang first flow ng heavy mestruation and red na red siya. After that naglagay ulit ako ng panty liner, meron ulit blood (red na red ulit siya) around 12 noon that time. After nun wala ng kasunod na blood until now. Ang expected period ko po is Sept 17 2021. Need ko po ba magpacheck? Stress din kasi ako lately, and i tend to overthink a lot. PS: I posted a pic of my pantyliner with blood, this the night of sept 11.