Is it permissible for a woman to purify herself and pray, and for her husband to have intercourse with her, if she suffered from a hormonal imbalance that led to a delay in her menstrual cycle then its advancement, and a small amount of blood (a few red spots) appeared and stopped after a short period, and this occurred two days before her original period?

If the blood spots cease, your husband may be intimate with you, and you are subject to the rulings of women in a state of purity, such as prayer. If the bleeding continues for a day and a night, you must perform ghusl (ritual bath) upon seeing purity, as this is considered menstruation. If it does not reach a day and a night, it is more cautious to also perform ghusl. After seeing purity, all the rulings of women in a state of purity apply to you.