Did it happen before or after?

Stacey • hello I'm a mother of of 5 n i.have a wonderful boyfriend that i love and 32 And we are having our first haby together.

So im almost 7 weeks postpartum and got the iud on the 8th. She did a test and it was negative so now I feel sick and something said take a test and its showing faint but not that faint on a dollar test and it has color . so did I already got pregnant before or did the iud failed me ?