Second period after c-section delivery very heavy with clots. is that normal?

Probably: As your body and its hormones adjust to the non-pregnant state, your menstrual flow will gradually return to its usual pattern. You may notice a difference in its timing, heaviness, discomfort, color as this adjustment occurs. If your menses doesn't become more normal or if you are having persistent and significant bleeding or pain or other concerns, may want to contact your ob. Good luck.