Can a test be negative and I still be pregnant???

Ok I'm about a week or two  away from my period but I took a test that came out negative...usually I have 30-34 days between periods. I've been hungry ALOT (healthy foods thank goodness) I've had a really touchy stomach and if I eat anything unhealthy I instantly regret it (burping with acidic taste of what I just ate) my husband and I have been trying for a baby for a while with no luck yet. Could I just not be far enough along or is there something else going on? I haven't been throwing up or anything like that but I want advice on if anyone else has been through something like this.