Question about Paragard

Lily • Navy Wife❤️Mom

I had the Paragard put in a month ago and I haven’t had a period yet. I just had a baby 3 months ago. My husband and I had unprotected sex a few times before I had the Paragard put in. The doc gave me a pregnancy test right before they inserted it and it was negative. Is there a way that the pregnancy test didn’t pick up the pregnancy hormone just yet? It’s just weird that I haven’t had my period yet.