In addition to postpartum depression, there are other conditions that warrant a telephone call to your doctor before the six-week visit. They include:
Excessive Bleeding. Heavy bleeding following delivery is completely normal. But many women want to know exactly how much blood is too much, and I have to say that it's hard to quantify. Excessive blood loss is associated with women who carried twins or triplets, because the uterus is so stretched out that it has difficulty contracting well. Excessive blood loss may also be due to retained fragments of placenta or an unrecognized laceration in the vagina. While some doctors take the number of sanitary pads that a woman soaks through in a given amount of time as an indication of whether the bleeding is excessive, I don't find this very useful, since women may change pads before they're completely soaked through.
In the hospital, the nurses take note of the patient's blood loss, but when she returns home she'll need to do that for herself. If bleeding suddenly increases after the two days, she ought to contact her doctor. (This goes for a woman who has had a cesarean, too, although typically she will bleed for less time-two to three weeks-due to a more effective cleaning-out of her uterus at the time of the delivery.)
Usually, the bleeding tapers off into "nuisance" bleeding for the next four to six weeks, but if it doesn't, or if it remains continuous and unrelentingly heavy or increases dramatically, this is considered excessive. You should call your doctor if you feel lightheaded or faint.
If your discharge is foul smelling, or if you develop an unexplained fever of 100.4 degrees, you ought to speak to your doctor.