pp period!

so aaliyah is 2 months and i already had a period last month but when i had it i hemradge (sp? soo wrong lol) also...i bled for 18 days, they gave me medicine and everything because they said my uterus wasnt contractin like it should and caused me to bleed more..now i got my period again for this month and i have been bleeding for 12 days straight ....again, could this just be a bad period..or should i go to the doc again in case i might have problems again? how long has everyones pp periods lasted?? just wondering..ugh im sick of this