Hey ladies I need some advice

I don’t want to go to the doctors office with this virus going around so I’ll ask here. I haven’t had my period in 30 days . I have an iud for a year and I still get my period monthly . I took a pregnancy test and it was negative .

Why would this happen ?

Could my iud suddenly start stopping my period a year in ? As iud are known for stopping your period .

I also don’t think I’m pregnant as I have an iud and pcos