Firstly, I completely agree with your GP in that the spotting may be caused by a lack of Estrogen. However, I am not a fan of synthetic hormones as they do tend to suppress your natural hormonal production. This, in the long run, messes with your hormones and it often leads to difficulties in future to restore your nature hormonal cycle. Because your natural hormone production is suppressed, you will need more synthetic hormones over time. I hope this answers your question. Women are often faced with mood changes and anxiety when natural hormone levels drop.