Hello, Thank you for asking at HCM. Normally women should not have dark colored tissue like pieces (coagulated blood) with menstruation but when periods are heavy this might happen. It is very likely it is OK in your case and nothing to worry. 1. If the bleeding this time was less than last month than I think you can just watch how you will be in the next month. If you have clots the next month, I would suggest you to: 2. Have a blood test to check if you are developing anemia- as I said above coagulated blood might be due to excessive menstrual bleeding and we need to make sure you are not developing anemia 3. Have a vaginal ultrasound: this will check how your uterus and ovaries are and especially if there is any mass in the uterus causing this. Fibromyoma is a very common uterine mass that might cause problem with uterine bleeding and not dangerous or serious but needs to be removed if it is causing heavy bleeding. The thickness of the inner layer of the uterus needs to be evaluated also 4. Make sure you have a check for STD especially chlamydia and gonorrhea. It is not very typical but is always advisable to rule out these infections 5. If you have not had a pap smear in the last 3 years or you had an abnormal one you will need to have a gynecological visit and pap smear done. 6. A gynecological visit is advisable even if you have had a recent normal pap smear. 7. If all the tests are normal and you have no uterine mass, normal thickness of the inner layer of uterus (endometrial thickness), pap test is normal, no infection found and no anemia than your doctor might try oral contraception to normalize your periods or progesterone treatment for some days in a month. Tranexamic acid is an option, Ibuprofen ect but you will need to decide this with your doctor. Hope this is helpful and answers to your questions Best regards,