hi there, though you say you had light periods last week it would be worthwhile to take a pregnacy test to rule out ectopic pregnacy given your history as implantation
bleeding can mimic a light period. If your preg.test is positive then get an abdominal or transvaginal ultrasound
done to rule out extra-uterine pregnany. In the mean while you could take some antispasmodics like mefenemic acid to relieve the pain. Take care.