IUD and discharge

Ok, so I got an IUD on March the 9th, first off when they say you will feel 10 seconds of cramping, that's a lie, I swear it felt like I got fisted by wolverine, anyway I  had bleeding for the first few days and then it stopped, but I would notice color on my toilet paper, didn't really think anything of. A few days ago, I got what felt like period cramps (my last period ended on March 7th) so I was thinking that it was to early but since my body is adjusting then maybe this is normal, and I'm sorry if this is tmi hit what's coming out doesn't look like normal period blood, it's a lot darker, more brown and has been going on for a few days now. Is this a normal thing to be dealing with? Side note I have a follow up next week to check for the strings. Please and thank you for your help