Period cycle

Monay

So I usually come on my menstrual cycle at the beginning of the month or at the end of the month, like right now I should be on my period or coming off my period. I thought I came on today when I wiped myself and I put on a pad now I’m not bleeding at all. I had sex like 3 days after I came off my period with no condom. I took a pregnancy test like a week after and it was negative. What do you all think this means?