BFP was false?

I'm wondering if anyone else has gone through this, because I'm so confused sad. My husband and I are TTC, and this month I started having weird symptoms about 5 dpo. (I went from being a strict vegan to craving chicken terribly, and I was really itchy in my legs at night, and was having a really hard time sleeping.) AF was due on 11/18, so I took a First Response early test on 11/13. It was negative, so I braced for AF. The rest of that week I continued with those same symptoms, but also had really weird painful cramping, but no spotting, and really sore itchy boobs. The 18th rolled around and there was no AF. My period and spotting in the days prior are usually very consistent and predictable, but I didn't get my hopes up. On Monday the 20th, AF still hadn't arrived, my boobs were killing me, and I couldn't sleep at all. I took a First Response Digital and it said Yes+. I was elated! The next 3 days were bliss. Then the night before Thanksgiving I started having weird strong cramps, and I started spotting at 4am on Thanksgiving day. The whole day then became about whether or not I was having a miscarriage. By Thanksgiving night I'm having a full on bleed session, essentially like a period. My sisters told me to go get another pregnancy test. So I took one Thanksgiving night, and one the next morning (today). They were both negative. So what I thought was a miscarriage is actually a randomly late period? That never happens to me. And I can't believe that First Response Digital was wrong. I thought it couldn't say yes unless it definitely detected HCG in your urine. But these 2 tests from today and yesterday obviously detect no HCG, and my sisters said my levels wouldn't have fallen that fast. I'm so confused and disappointed. Has anyone else gone through something like this?