15 dpo... 2 days late

Ok so I'm not 15 dpo and I'm 2 day's late. But I'm still getting negative pregnancy test. I'm new to trying part but my period is never late. The only two times in my life that it's been late I've been pregnant. I don't know what to think. I'm stressin big time because we only have a limited amout of time before deployment. Plus my birthday is in two weeks and I wanna know before then and before my husband goes into predeployment training.... I HATE HATE HATE waiting!