I'm breastfeeding my son who is just over 5 months old. When I'm at school he usually takes one formula bottle. My…

I'm breastfeeding my son who is just over 5 months old. When I'm at school he usually takes one formula bottle. My fiance and I are getting married in September and want to start trying for baby number 2! However my monthly hasn't returned. Have any mom's been able to conceive while breastfeeding? Any tips or advice is welcome!