Wanna check if any mummy get pregnant while breaatfeeding and no menses yet . Is it harder?

When I am trying for baby no.2 I have faced difficulty in conceiving due to no mense. I breastfed my no.1 until she was 3 years old and finally my mense has returned and I successfully conceived my no.2 after one period cycle. While breastfeeding no.2 I have no mense too and I thought it would be the same case that I am difficult to get pregnant without mense. But I am wrong! I conceived no.3 when my no.2 is 2 years old without mense. Thus, I would say it is true that harder to get pregnant while breastfeeding especially if there is no period as you do not know when will be your fertile timeline. However it is still possible to get pregnant while breastfeeding.