how long does mirena cramping last?

Anna • ✌🏻️✌🏻
Howdy! I just got my mirena put in almost 12 hours ago and hollyyyyy shit, the cramping is almost like I'm on my period again (and I have heavy, awful periods) 
When does it end? I have a heating pad and I might smoke a bit of cannabis indica to help with the pain, but is there anything else that might help?