Bfo and period

Question: Anyone get what they thought was their period but wasn’t and ended up actually being pregnant??

My situation: So Im 4+2 currently my period was due on monday. Late sunday night/monday morning I started bleeding it started brown then it went on to become a flow i thought it was my period but i guess it wasnt lol the first day i would say it was medium flow and today i woke up with no blood all day it was brown spotting then i started light bleeding (just like one quick gush but not a consistent flow) and then brown spotting again and its pretty much done now. My usual periods are 4-5 days long with the first 2 days super heavy and the last couple days light to nothing. Well i took a test and it came back bright red bfp.