Ay, first period talaga yan ng anak mo? Kailangan mo talaga mag-consult sa pedia or OB niya agad, lalo na kung 11 days na at malakas pa rin ang dugo, normal lang ang first few periods na irregular, pero ganyan katagal at intense ay hindi usual, so better safe than sorry talaga. A few of my mum friends had similar concerns and their doctors just did a quick check para ma-rule out kung may underlying issue lang, so don't worry pero huwag din i-delay ang appointment ha.