I have been having a lower back pain. always felling tired. bloated irregular periods sometimes spotting light pink or brownish. am having pains on my stomach. and i have had a black stool?

It is not feasible to provide a meaningful opinion without additional history, physical examination and may be some tests. Of particular concern is the black stool that may indicate bleeding in the stomach/intestine. It would be prudent to see a doctor. Wish you good health!

See your doctor and have an examination to determine the cause of the symptoms. Good Luck