Confused as hell

Had my baby 4 months ago, last month I had my period, this month I am 5 days late glow days. Is it normal to have irregular periods?? I’m not on any contraception or breast feeding. I took a 6 days early test which was faint but looked more indent about a week ago now. The another one 4 days ago different test that said negative. I’m so confused ☹️☹️