11months postpartum and just have my 1st "period"

Jackie • Baby boy born 10/17/16 Baby girl 09/14/18 🤰 with #3

Started my first postpartum period (I think) yesterday. But then I took this???

Definitely confused? We had sex June 30th I feel like it Shld be more positive if I was pregnant? We also had sex last weekend but wouldn't that be to early?!