HELP!!

So according to Glow I am 2 or 3 days late on my period. Now my fiance works offshore and when he is home (3 weeks) we had sex pretty much everyday. No source of birth control or anything. We are trying to conceive. Now period started a week early and was pretty much Normal from there. We still continued to have sex. I started ovulating the last 3 days he was home. Like I said I am 2 or 3 days late and he left 2 weeks ago. I haven't been cramping, but I did get extremely dizzy for just a second the other day while sitting down and I've also been bloated and a little constipated. Sorry for TMI! I have taken a test. I took it the day i was supposed to start my period but it was negative. Please any advice or help?!