Hello Thanks for your query. Pain in the lower abdomen could indicate possibility of preterm labour. That is when the uterus starts contracting before term. Isoxsuprine is Duvadilan which is a tocolytic, that is , a drug that relaxes the uterine muscle and is used to prevent and treat preterm labour. Your obstetrician must have found risk of preterm labour in your case, which is why, duvadilan was prescribed to you. It is safe to take the medicine for 3 days as prescribed to you. Meanwhile, avoid stress, intercourse, travelling etc. Take adequate rest and maintain hydration. All the best.