All the symptoms are there and I got a positive digital but the doctor says no?

I'm not entirely sure how to go about asking for advice on this particular situation but I have reason to believe that I am pregnant.

To give some context:
The last time that l'm positive I had my period was July 12th. Also the last time I was intimate with my partner whatsoever was on the 27th of July.

About a week after the 27th I just randomly got this really horrible headache and was lethargic out of nowhere but I completely ignored looking into it because the next day I was informed that my partner had passed. About two days after the news I started bleeding. This was odd for me because it was two weeks earlier than my usual period and lasted twice as long. To add onto the odd timing it was also brown which was also very weird for me. I attributed it to stress and grief thinking it may have just started early.
But then about a week or so after that I started "bleeding" again but it was just pink and lasted about three days. During this span of time I had gotten two pregnancy tests taken at my primary care checkups but they had turned up negative. l just decided to continue on with my life thinking maybe I was just hopeful to be pregnant so that I could have a piece of him with me forever, but now symptoms are coming at me full force.
I'm having lower back aches all the time, this yeast infection that goes away when I take monistat but comes back 2-3 days later (which is abnormal for me-especially when not sexually active), this weird fluttery feeling in my stomach everyday, headaches, sensitive chest, I’m suddenly quick to tears, and no food sounds good to me at all which is not normal for me because I'm a big eater.
I bought a four pack of clear blue tests and over the span of a week I took them. I got one negative digital and two faint line strip tests. I thought maybe they were evaporation lines so I just went to use the last digital to just get it out of the way but it came back positive. I was elated. I made an appointment with the OBGYN but when I arrived she couldn't see anything with my TV ultrasound. She saw my disappointment and suggested maybe it was just too early to see and that we could do a blood test, but that didn't necessarily sound correct to me because at this point l'd have to be about 7-8 weeks.
We ended up doing the quantitative blood test but the results came back as only 1 hcg which is obviously negative. I was crushed and when I went home i bought two more strip tests from the dollar store in a desperate attempt because I know digital false positives are rare. But they came up negative again.
My friend wants me to go get a second opinion because her mother dealt with the same thing when pregnant but I don't want to give myself false hope. I want to just trust the doctors but the symptoms aren't going away and something in my intuition is telling me I am pregnant. I'm just wondering if anyone has any insight or if there are other moms that may have experienced this during their pregnancy or knew anyone who went through the same thing just to find out that they were indeed pregnant.

Thanks in advance to any and everyone who has any input!