Weird period situation

Summer

Hello

I’ll be 40 in October and I had a baby 8 months ago. My periods resumed in April or May and were fairly normal. Then in July I had a period 15 days early and have yet to start my period so I’m a good 9 days late but not pregnant (took 2 tests) Anyone ever experience this? Is it just strange post delivery periods even though they were normal for a while? Is it early menopause? That would suck since I would love to have another baby!! Thanks for any input.