When will my period return

Okay so with my daughter I exclusively breastfed and my cycle returned at 3 months PP this time around with my son due to medical reasons on his behalf I have to supplement with a doctor prescribed formula just wondering if that will bring my cycle on as soon as six weeks or is there a chance because I am breastfeeding that I can still go a few more months before my cycle start has anybody experienced this of course with a pregnancy besides the one that you are postpartum with at the moment unless you have already gotten your postpartum period From this birth that you have given