Liletta IUD & no bleeding after insertion when I was due for my period the day of insertion ???

So I got the Liletta in yesterday. I bled heavily for about four hours and the rest of the night I had brown bleeding and this morning I had brown discharge which went away. I'm confused because I was supposed to start my period today and it hasn't came. I took a pregnancy test at planned parenthood before they gave me the IUD and it was obviously negative, but I'm still really paranoid. I got my previous IUD out in October and bled from nov 22nd until Christmas pretty much every single day. My last period was dec 22nd until dec 28th, before that it was dec 10th-15th, then nov 26th-Dec 3rd. With spotting lightly in between those days. So I've basically had a nonstop period from not having the iud. Im still kinda having on and off brown discharge but still no signs of period. My last two IUDs I had, I bled for like 3 days after getting them in. This time, no bleeding. I was thinking that the IUD totally cut off my period but I haven't had it in for 24 hours yet ?