Postpartum period


I have had my period 3 times now since giving birth in April. I had one July 22, August 20, and September 17th... I haven't had my period this month. I don't have any PMS symptoms, and past periods were painless. I am sexually active but we have been pretty successful making sure to not have another baby. I was wondering if this is normal or if anyone has experienced this? Thank you for taking your time and reading.