Period

After 4 months and 13 days after having my boy I started my period I had sex had an accident and didn't come one tested weeks after all tests even doctors test come back not pregnant my little man is 6 months old and on the 20th of June it would have been 2 months since I was last on if I don't come on this month could it be my body still getting its act together after birth or should I go to docs about it as I already did come on.