Is it necessary to re-pray Fajr if menstrual blood flows at the time of Duha or Dhuhr, with the emission of intermittent bloody discharges and veins the night before?

What you saw of discharge is menstruation. If it had ceased and you saw complete dryness, then you should have performed ghusl and prayed, because the period of purity that interrupts menstruation is a valid state of purity. Therefore, when the menstruation ends, you must make up the prayers for the times when you were pure. You are not required to make up the prayers for the times when these discharges encompassed the entire prayer time.