IUD/ Pregnancy

I have the Paragard and I have classic pregnancy symptoms. I've taken a test and it came out negative, but my period isn't due for another week or so so it's possibly too early to know. Is it possible to have symptoms only a couple of weeks pregnant? Could I be further along and the urine test just isn't picking it up? My last period was unusually light but it was more than spotting. I usually have a really heavy flow but this isn't the first time I've had a small period though. I'm trying not to freak out but if I am pregnant, it's very dangerous and high risk for me and the baby. I know that in most cases where women conceive with an IUD in place, the pregnancy is ectopic. If I am pregnant, and it is ectopic, could that also be why I got a negative test?