Thought I was pregnant

I had sex with my husband and the condom came off... Whoops. And so I knew the day and was watching my body carefully to see if I had any symptoms. I seemed to have ALL the symptoms, nauseous, tender breasts, fatigue and more. I took a test and it was negative, but it hadn't really been very long so I waited and I didn't get my period. I usually get it 2 days early and it didn't come. I took another test on my second day of missed period and it was still negative. 3 days late and my period comes. I was thinking maybe it was just implantation bleeding, but it's dark red and has clots. I'm so disappointed. I wasn't planning on kids but now that I thought I was pregnant and started thinking about it, I'm so sad.