I would recommend going to see your primary care doctor
or your OB GYN doctor about this issue, especially if the cramps are not getting better after a few days. The fact that you already had your period last week means that other causes of cramping need to be considered other than just plain menstrual cramps.
One thing, for example, that will need to be ruled out is a sexually transmitted infection, such as chlamydia or gonorrhea. In addition to cramping, these may also cause other symptoms such as burning with urination or vaginal discharge.
At the same time, a urinary tract infection
would be another common cause of lower abdominal cramping, typically associated with other urinary tract symptoms, such as burning with urination or having to urinate very frequently.
Finally, cramping may not be related to the reproductive system or urinary system at all - for example, constipation is a common cause of lower abdominal cramping.
Start by making an appointment with your doctor at your earliest convenience. In addition to a physical exam (including a pelvic exam) they will probably want to run some basic tests on a urine sample. Based on what they find, they will be able to recommend any necessary treatment.