ive had the same thing, so im guessin that its normal...i just assumed that it was everything shrinkin back....
but if u dont fell that its that then mabey u should call ur doctor...
but i know i had experienced this pain till my first period ater i had my daughter...and she is 2 months old now...and i still find a sharp pain every now and then....

Some degree of pain or discomfort is normal as your body adjusts from pregnancy back to your pre-pregnant state. I was not able to find any information on why a specific pain like the one you are describing should suddenly begin a month after delivery. If it persists or becomes worse, give your doctor a call and let him know what is going on. It is possible that the pain is connected to something not related to pregnancy (gall bladder, appendix, etc), so be sure to get checked if it continues or gets worse. Let us know what the doctor says, and good luck. :-)

I had pain and discomfort after delivery for about 6 weeks, then it started to get less. Its normal to be uncomfortable and have some pain to some extent, your abdomen is tender. At your 6 week checkup you could mention it to your doctor. Some of the afterpains can be your uterus contracting back to normal, or constipation. If you had a vaginal birth this is a good link. http://www.mayoclinic.com/health/postpartum-care/PR00142 I hope you start feeling better soon!