PLEASE HELP!

So I'm having a bit of a hard time understanding everything.

My last period was July 21st-23rd. I ovulated on August 4th. My period was due this month between the 19th-21st. It always varies those days but it's never no later than the 22nd. Here it is the 28th and it still hasn't arrived. I've been testing and getting negatives. I've been having pregnancy symptoms, but it could just all be in my head. This morning I tested and a line popped up within 4-5 minutes but disappeared by the 10 mintue mark. Not sure if it was an evap line or what. Does anyone have any suggestions on what to do? I'm waiting for my dr to have an opening so I can be seen.