Must I make up the days during which I continued to fast and pray while experiencing a second menstrual period in Ramadan, considering it as irregular bleeding (istihadah), especially since the color and smell of the blood were different from usual?

If blood appears before 15 days have passed, the woman should add to her usual period until it reaches its maximum duration, and then she is considered pure. For example, if her usual period is 10 days, and she stopped praying for a week then the bleeding stopped, she should perform ghusl and become pure. If bleeding resumes before a complete period of purity (15 days), she should only count 3 days as a completion of the ten. Some scholars hold that she should add 3 days to her maximum usual period, provided it does not exceed 15 days. After that, any blood becomes istihadah (non-menstrual bleeding) and does not prevent her from any of the things that menstruation prevents. She should continue in this state until the bleeding stops for 15 consecutive days, or if her blood shows distinguishing characteristics. If the bleeding stops for this period, or if she distinguishes it after 15 days of istihadah, the discharged blood becomes a new menstruation.

If your maximum usual period is 5 days, then the blood that appears before the completion of purity is considered istihadah. However, if your usual period is more than 5 days, then you should add to the bleeding to complete your usual period, along with adding 3 days, provided the total does not exceed 15 days. Changes in color or smell are not considered unless the bleeding exceeds the maximum usual period. Continuing to fast during the second bleeding period is incorrect if you have not completed your maximum usual period, and you are obligated to make up for the fasting days that complete your usual period.