No periods yet. Have questions

Hi

My baby boy was born on 5th April this year. I had periods on 18th May. After that still have no periods. Exclusively breastfeeding only. This is my first time ebf. Read on google that ebf periods may come late. I did checkup too cause of having some pelvic pain.. dr said endometrium is mild thick. Now i have no idea what the pain is. Dr gave lots of antibiotics to treat fungal infection down there. If that maybe the cause. But its still there the pain. Cant move. Idk. Well, i mainly wanted to get ideas regarding the periods. Anyone same ? Because there is no periods so endometrium would be slight thick right?