Long periods with IUD?

well i had a baby 2 months ago and after my 6 weeks check up i put the IUD and i spotted the whole day that day when i got my IUD inserted but after that i stop spotting that day ..like a few days after that my first period came after 9 months of being pregnant so i was like well maybe it will last less because i have the Mirena IUD ..i got my period the 15 of this month and is June 27 and still haven't left i told my doctor the other day that i had to go for a follow up to check the IUD if everything was OK with it and it was in place and yes it was perfectly fine in place and everything and she said the period was gonna leave by itself the reason why my period have last so long is because the IUD ..but i am not liking that i want to be intimate with my partner and its lasting so long to leave when is it going to leave ....