Hi, The chances of pregnancy are very low in your case. The only reason for this is mirena does not always prevent ovulation. But it does make the cervical mucus and uterine lining unfavorable even if pregnancy occurs. Also you have had bleeding which again disfavors pregnancy. Symptoms of pregnancy do not come until atleast after 2-3 weeks after conception. It is only 1 week ago that this episode occured. So they are not due to pregnancy. Sore breasts and itchy nipples are more suggestive of either infection or dryness. If the itching is due to dryness, use a moisturising cream. If the itching is severe, there is redness or disclouration of skin, an infection is likely. Use a topical ointment containing mupirocin and clotrimazole thrice a day and keep the area clean. Do not scratch. It will be all right. I suggest that you do a pregnancy test 3 weeks after the sexual episode. If the test is negative pregnancy would be ruled out. Hope this was helpful. Have a good day and do not worry. Thanks for using HCM. Dr. Madhuri Bagde Consultant Obstetrician and Gynecologist