Thanks for your question.
This is most likely to represent a terminal part of your period & is likely to settle in 2-3 days. If this continues beyond this time you should see a doctor. preferably a Gynecologist to find out the cause of this abnormal bleeding.
If you are not on a reliable birth control you must also exclude pregnancy
If cramping is sever you must go to the hospital as soon as possible as this may represent an early pregnancy complication like ectopic pregnancy.
Wish you good health.