Thanks for your query.
Since you have not mentioned the age of the pregnancy, it will be difficult to tell you the medicines. This is so because in the first 3 months (first trimester) of pregnancy all the medicines are avoided.
Secondly, it is most important to know the cause of such a severe pain, hence it is imperative that you take her to ER / talk to her Gynecologist and get an opinion and treatment possible. Do not give any tablet at home.
For the time being you can apply locally the Rubefacient creams, which make the area warm, ask her to take strict bed rest till seen by a Doctor.
I hope this answer helps you.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.