Negative test help

So I lost my virginity in June and I've had two on time periods that were just like any other since then and I took a test about 2 weeks ago and it was negative but I can't help but fell like I'm pregnant. My boobs hurt. I've had some nausea, metallic taste which have gone away a while ago but my boobs hurt still and have grown a bit but I don't know what to do. Is there anyway I can know for sure? Has anyone had their period while being pregnant? Amy advice? Could this all just be in my head?
Also my period is due in 6 days should I wait to see if it's any different?