Spotting

I’ve been brown spotting sometimes light pink since 21st of last month I was told it’s a period but I’m not bleeding it only shows on toilet tissue and not on a pad the 22nd of Jan I bleed heavy but that was the only time and that was when I waked up then it just went away like I didn’t bleed heavy it went back to spotting that same day I was suppose to have period on the 22nd and so I took a pregnancy test. Negative even a ovulation test negative have anyone experienced in before? It’s going to be going on 3 weeks next week on Thursday’s if it don’t stop.