first thing you need to do is relax.. any women after giving birth will have a certain period of time usually up to six months when she does not undergo her usual menstrual cycles.. this is because of the hormone known as prolactin
that is responsible for milk production.. so when the baby has been fed properly then the hormone levels will be maintained at a high level which will prevent ovulation and there by pregnancy
.. this is natures way of protecting the mother from stress
of another immediate pregnancy..
once the hormone prolactin starts to decrease the body prepares for its regular menses.. so most probably it looks like this is the same process happening in you..
about the other symptoms that you are mentioning those will occur intermittently as long as the pregnancy related hormone present in the body gets depleted.. that is all..