Very down and not feeling like myself

Okayy so my baby was born on june 1st.shes an absolute joy! Shes such an easy baby...laughs a lot and only cries when shes hungry or tired and wants to be put down...however, for a while ive been feeling down and i dont know why. I know Im extremely tired, but thats normal my baby is almost 4 months old. Ive been reading a lot online and came across things such as ppd. But i read that women with ppd dont bond with their baby whilst im absolutely crazy about my baby! I miss her when shes not around....anybody experiences the same thing? Could it be a beginning of ppd? Or will it just fade away over time??