Hi, Welcome to HCM. You have not mentioned if you suffer from the same type of problem after your periods end. Having abdominal cramps, lower back pain, sore breasts, nausea, etc are known as dysmenorrhea and is a normal condition experienced by most women. It may start a day or two before the periods begins and ends up as the period finishes. This time your period did not last for 5-7 days as it normally happens, if you had an unprotected intercourse, get a urine test for pregnancy done. This is for you to stay on the safer side. If you are not pregnant the other reasons can be PID, ovarian cysts, fibroid, endometriosis, etc. You should get clinically examined and get investigations like USG, pap smears, vaginal/cervical cultures, blood tests done. Consult your gynae and get proper hormonal therapies, antibiotics. Depending upon the diagnosis you may have to under surgery for fibroids, etc. NSAIDS can give you temporary relief, take care.