This is so weird, anyone else experience this?

Christina
So here I am now 2 months late on my period. LMP was 6/16/15. I have taken countless hpts all negative. Went to the ER for abdominal pain where they did blood work. All negative. However boobs are tender, pants are getting tighter, emotional, headaches, heartburn and nausea. I have had two children and NEVER been late on my period unless I was pregnant. Anyone else???