IUD Question

Jamie
So I recently got an IUD placed. Monday the 12th to be exact. (Mirena) The procedure was pretty painful (getting your uterus depth measured. 10/10 would not recommend for a fun Friday afternoon lol) but the cramping afterward went away the next day. I was on day three of my period (I usually spot for almost a week before actually getting it) but since getting the IUD I've been bleeding pretty steadily. I would say light bleeding since I only seem to get blood and clots when I wipe and rarely have much on the pad I'm wearing. 
Now my obgyn said as long as I'm doubled over in pain or bleeding buckets I should be fine, and I've checked for the strings a couple times and it seems to still be in place. But is bleeding for almost 2 weeks after placement normal? I know she mentioned spotting or irregular periods are a possibility for a few months. Just wondering if I should be concerned or not. Thanks for any support guys!