Please bear with me:

 

I have a normal 27-28 day cycle. I have 3 children—a singleton and twins (born vaginally). I am never late, only a few days early occasionally. I bleed very very heavy for 5-7 days every month. 

This cycle, my husband and I had sex during my fertile window. A week before my expected period, I started to feel off, experiencing a number of pregnancy symptoms. I took a HPT 2-3 days before my expected period and it came out so so faint, I thought I was imagining a line. Same thing on Saturday. Same thing on Monday. I thought I was feeling implantation cramps the day before my expected period, so I figured I was just barely pregnant. 3 days after I missed my period, I went to my doctor for blood work to start pregnancy care right away (especially since I had fraternal twins and am likely for twins again). That night (Tuesday) I started bleeding and went to the ER. Both blood and urine tests were negative. They told me I was not pregnant. Confused, I went home and expected to have my usual 5-7 day period. I had moderate bleeding all day Wednesday, had bleeding on and off on Thursday, nothing on Friday, spotted once on Saturday, and have had spotting (brown) Sunday morning. I took another HPT this morning and it was negative. I can accept if I had a chemical pregnancy, but I'm wondering where is my period. I've been having headaches, dull cramps, frequent peeing, and heightened sense of smell. Should I continue to test if I continue to only spot. My cervix feels closed. Possibility I'm pregnant? Should I be concerned?