Mirena IUD question ?

So I got my IUD 6 days ago and it went well I was on birth control pills prior to that and didn’t get my period after stopping so hence getting the iud put in i didn’t have my period yet so 3 days after getting it I started bleeding like a period .. and it’s been the same for last 3 days like a semi heavy period.. so my question is , is this normal has it happens to anyone before and what did you do ? I don’t have cramps or anything just bleeding ?! 😌