Confused, anxious and can't sleep!

Sam
Hi Everyone!
According to the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> my period was suppose to come on Aug 23rd (My birthday). Now it's Aug 27th (my husbands birthday) and still no sign of it. We took a HPT earlier today and it was negative. I googled everything under the sun and read that it's possible to be pregnant and still get a negative result on a HPt. What's even more confusing is I thought I was experiencing cramping last week now ever single time I go to use the bathroom I check for my period. It's making me a little nuts not to now what's happening with my body right now.  I'm just not sure what to do at this point and I don't want to get my hopes up.... At what point is a late period considered too late. I've never been late more than a day before and even that is rare. The <a href="https://play.google.com/store/apps/details?id=com.glow.android">Glow app</a> is usual accurate for me. Any insight?