Periods returned but no positive OPK

Kay

So I got my period July 20th and bled for exactly five days. It was just like that before I got pregnant too so I was hoping maybe my cycles would just resume like before. My daughter will be 1 on the 10th and she still nurses frequently through out the day. I’ve been using OPKs and have not had a positive yet even though my app says I should ovulate today. Is it possible I could still ovulate this cycle? Any tips or tricks to get regular cycles? Do you ladies experience irregular cycles while still breastfeeding? Thanks in advance for any advice!