I don’t think so. My mother had no issues conceiving and breastfed my and my three siblings. She said she basically got pregnant shortly after getting her period back with each, and we’re all 2.5-3 years apart. I had issues conceiving my first and second, and agog my period back while weaning around 13 months. My periods have always been regular and suspected issues are endometriosis and male factor. Not 100% sure if my fertility is the issue though.

i had to do ivf with my first, then got my period around 9 months pp (still breastfeeding prob 5 times a day) and got pregnant naturally 4 weeks later (weird long cycle)

I conceived the first time trying at 34 and 36. I did not get my period until 6 weeks after my last nursing session for each kid.

This is OP and I appreciate the replies! From our sample, I agree there is no correlation. Thanks everyone!

I was going to submit my own answer but... what's the point? It looks like there is clearly no correlation.

My period did not return until I fully weaned at 22 months, and then it returned the first month after weaning. After 12 months, I only nursed twice per day, and only once per day the last few months. I got pregnant my second cycle after weaning. Now 9 months post-partum, still nursing, and no period.

I was not super fertile (DOR at 33) and my period returned at 5.5 months while nursing twins.