Hi and welcome to Healthcare Magic. Thanks for your question...
Such severe lower abdominal pain
is not a usual side effect of 'unwanted 72'. Moreover, such pain occuring after 12 days of taking the medication is very unlikely to be due to the medication. So, your abdominal pain is due to some other cause which needs proper evaluation and need urgent attention.
Please consult a doctor immediately for a detailed evaluation and appropriate treatment.
Wish you all the best.
- Dr. Jonas Sundarakumar