Could I be pregnant again? I need advise ladies please !

So my baby is 4 months old now. I had my first postpartum period on August 13-19 and now I’m 23 days late. Completely missed my period last month. I did a test and it came back negative. I took it 9 day after my missed period. I did read where it said I could experience irregular periods but should i completely miss it though? I feel as if I’m gaining weight. My boobs hurt and My baby is ebf. Does anyone have any experience like this or know of anyone who does?