Pleas help 😭

Hi everyone quick question, I had light spotting about a week after taking plan b, my period is late for 19 days now, and I’ve taken two pregnancy tests last week they both came out negative, we also used protection when having sex, I just took it as an extra precaution. I know that your period can be late for a while when taking plan b but I started having some discharge that looks like dark blood, last night we fooled around a bit and when I went to the restroom and go to wipe it comes out on the paper as blood but I put on a pad and nothing. Is this my period but super light? To the point where it doesn’t show on the pad? Or is it something else? Like when I wipe there is still blood, and I have cramps since Saturday.