Diaper change. Accidently or unknowngly.

My baby is 8 month old.. Usually I change hes diapers after every 3 or 4/hours...but day before yesterday she slept early at 8pm....she woke up at 11 am next day...means I changed her diaper atleast after 15 hours.... Since then I am worried does it have effected her in long run...though the diaper companies claim to b absorbent for 12/hours... Can we make them wear for this long... I never do the same...but somehow I forgot to change at night as my baby didnt wake up at night and if I had woken her up she wud have hard time to sleep.... Now I want to know will she have infection by all this...will there be any problem if I  accidently or unknowngly ..left diaper fr many hours....someone told me she will have uterine problem...I aam so much worried by this Please docs reply... I am so much worried