Breastfeeding and periods

Has anyone had this or a similar experience I am currently 4 months Postpartum and combination eating my daughter My period returned at 7 weeks postpartum and then the month after that was normal the third month it was a week late but it came this month it's already two weeks late and I don't think it's coming has anyone had there period come back but then disappear while breastfeeding *** Side note my husband had a vasectomy and I also took two pregnancy test to be should she I know I'm not pregnant