Started early... Confused TTC

So the last day of my period was July 18 and I started spotting two day ago I took a test three days ago and it came out negative.. And now today I have started bleeding more.. I've also been very sick to my stomach the last 4days and have even thrown up a couple of times and sore down stairs and up stairs (if you know what I mean) and I'm not due to start until the 5th! Any opinions??