Breastfeeding mamas, how long for your period to return?

Hi for those who have breastfed with previous babies, how long did it take for your period to return so you could try to conceive again? I have read it can take up to 
12 months if you breastfeed versus sooner after birth doing formula...we are hoping to conceive a year year half after this one is born (God willing of course) so just curious on your fertility returning while exclusively breastfeeding. Thanks so much