Late period with pms symptoms...?

Ok, last period was June 30. Had July 10-13. On the 16, started spotting light pinkish brown for four days then stopped. Period was due July 30....but never showed. I was nauseated on and off a couple days ago (mostly in the morning and slightly at night). I am VERY bloated, I usually do not get this bloated before my girly thing. I keep feeling like it is on its way, but nothing! Stomach cramps on and off and headaches every evening between 6-9 pm. It is like clockwork! I have been tired but I do get tired before AF. Therefore, I have taken two pregnancy tests. One from the dollar store and the other from Planned Parenthood...both negatives. Ii am getting a blood test tomorrow. But has anyone gone through this?? Thank you!