Period 3 days late & then HEAVY bleeding for 2 days?

So my period this month was 3 days late, I took a pregnancy test on day 2 of no period and it was negative, I finally started and only bleed for 2 days and it was extremely heavy and clotted the first day and then the next day it was just spotting, that ended on Friday! Today (Monday) while at work I noticed when wiping hat there was some brown blood on the toilet paper?! My periods are always pretty consistent and I’ve never been late besides when I found out I was pregnant 3 years ago! Should I go get another test to make sure or would you think there would be no way of pregnancy! The last time I had sex was around 3 1/2 weeks ago!