Don't want to wean but I want to get pregnant

Rainbow
My baby is 1.5 years old and still nurses to sleep for naps and bed time. We haven't been preventing for like 6-8 months and have been actually trying for the past 3 months but I'm still not pregnant. I'm pretty sure it's because I'm still breastfeeding but my baby isn't ready to wean and neither am I. Is there anything I can do?