I need some outside opinions

Okay I take my pill pretty accurately I may be late by a few hours due to work but I take it every day. The last time I had sex was on Nov. 17 and my period was Nov. 12-Nov.16, I was suppose to start my period Sunday and i didn’t. I had some brown discharge yesterday lien how I typically do when I start so I thought I was gonna start and I didn’t. I don’t think I’m pregnant cause I would be like 5 weeks and I have no other symptoms whatso ever, no breast tenderness, no cramping no nausea no food cravings no mood swings nothing. I kinda just want other people’s opinions on this since I haven’t told my boyfriend. My friend thinks it was just cause of stress from my finals this week but I didn’t feel very stressed and I guess I’ve been kinda worried since I haven’t started which has stressed me out.