Hello I appreciate your query Since you had an irritable uterus, you must have been put on Duphaston and Cyclogest, which are various forms of progesterone , given to relax the uterus. Progesterone acts as a uterine relaxant. Hence, it is safe to continue taking it as long as your obstetrician prescribes it. Cefditoren pivoxil is safe for all trimesters and falls in pregnancy category B. Pregnancy category B means - Animal studies have revealed no evidence of harm to the fetus, however, there are no adequate studies in pregnant women OR animal studies have shown an adverse effect, but adequate studies in pregnant women have failed to demonstrate a risk to the fetus. Hence, if based on some tests or investigations, your doctor has seen the need to prescribe Cefditoren, then you may take it without worrying. There is no problem in taking the medicines together, as long as you space your medications. Hope this helped you. You can contact me at the below link for further clarifications : http://www.healthcaremagic.com/doctors/dr-aarti-abraham/64623