While on hcg
diet it will be better to be informed from the literature available with the product regarding side effects of the product.
It is basically a hormonal
product that regulate the metabolic functions during pregnancy
some times ovarian hyper stimulation syndrome may occur .
As you are having pain lower abdomen ,better will be to get a check up with gynecologist and an u s g done to rule out any abnormality.
intercourse on 8th july and lmp being 4th july rules out any possibility of pregnancy .The bleeding may be due to some hormonal changes . please get a check up and take treatment as required.
Hope you be all right soon