Am I really super fertile postpartum?

I have a 5 year old a 3 year old and a 16 day old and anyway my births have always been text book with minimal damage well I just get up and walk away really I don’t even scratch bleeding lasts a few days (vaginal birth) anyway me and husband got carried away last night and had sex. I’m not really wanting to fall pregnant right now but I wouldn’t be disappointed if I did either as a family is all I’ve ever wanted (secure relationship of 15 years) I then remembered the midwife saying I’m super fertile right now. Is there a chance or is it more of an old wives tale? Again I know any unprotected sex can lead to pregnancy but are you really as fertile as what they say