If you’re period hasn’t returned it’s unlikely that you’ll be ovulating. I had to stop breastfeeding entirely for my period to return and it took 10 months as my cycle took a long time to become regular again after breastfeeding 😊
I’m exclusively pumping but my period did return while I were exclusively breastfeeding a couple months after I gave birth and I’m currently pregnant 🤰
You could try tracking ovulation to give you an idea- LH strips or tracking your bbt etc. How old is your first baby? Do you feed overnight? Of course it’s possible to conceive before your period returns if you catch the first ovulation and are successful, but it definitely is trickier when your cycle hasn’t returned yet. I did get pregnant whilst BFing my eldest, but my cycle had returned when we decided to ttc.