Returned after 45 months of breastfeeding

My period recently returned on August 26th for the first time since I became pregnant with my first in December 2011... I then became pregnant again December 2013 while still nursing my first (would've been my first ovulation cycle) and my daughter nursed through that pregnancy. I had my son in September 2014 and he is still nursing. My period has not returned this month. Because I haven't had a period in so long (45 months) and because I'm still nursing, I'm just wondering what to expect?