first period after the miscarriage, bleeding so heavy!

Hi,
Welcome to ehealthforum,
Heavy bleeding with presence of clots could indicate possibility of retained products in uterus (after miscarriage). If you had been sexually active without protection during the first few weeks of birth control pill use, chances of repeat pregnancy and probable ongoing miscarriage are also possible. Other possibilities include hormonal derangements, thyroid abnormalities, endometrial hyperplasia, bleeding disorder (could be precipitated by birth control use), etc. The exact cause can only be made out after careful evaluation. Consider visiting your doctor/gynecologist at the earliest for thorough examination and further evaluation to look for the underlying cause for the abnormal dark vaginal bleeding that you describe. Treatment as appropriate (based on examination findings and investigations results) would be started to help you control the bleeding and regulate your periods. Consider being in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Drink plenty of water. Take adequate rest. Maintain healthy diet and lifestyle.
Take care.