ovulation kits? breastfeeding...

Hi ladies. Sadly, AF showed up 😞 I was a week late so hoping she was gone. 
I have an 11month old who is EBF.... I got my period in July and it was regular until  this month. My dr said that while breastfeeding your cycle can bounce around. 
Any ideas of when to use ovulation kits?? TTC#2 and wanting to figure it all out before I miss the ovulation window. 
I really appreciate the help.
Baby dust to everyone!!!