Eh, day 37 pantang and sudden bright red bleeding dengan cramping sounds like something worth getting checked out lah, especially since you had a caesar, better to call your gynae or go to the clinic just to be safe, kan, especially if the bleeding gets heavier or the cramps get worse. A few of us mummies experienced different lochia patterns after surgery and the doctors said it's better to rule out infection or other issues, so don't worry about troubling them, that's what they're there for! Keep an eye on it in the meantime and rest as much as you can, okay.