Irregular/missed period 12 months pp

Cheyenne • I an 27 and I have a 3 year old boy, 6 year old boy, a 7 year old little girl, and 16 month old little girl

I am a year pp with my 3rd. I got my first full normal period last month. I am now a week late for my period. I took a test a few days ago and it was negative. I have all kinds of pregnancy symptoms though and I don’t know what’s going on. I usually show positive before I ever miss my period so I’m confused. Anyone else experience this?