TTC while breastfeeding and regular periods

Tiffany

So I have been breastfeeding for 12 months and my period came back like 2 months after I delivered my son and I have been TTC for 3 months now and I have not been lucky. I have been tracking my period on this at and I have been bd a couple days before ovulation and on ovulation still nothing. I also been checking my cm to see if I get any fertile cm and I have been getting some but I still not pregnant please help any advice