Help! What do u think

I had a miscarriage at 5 weeks on August 12. Levels were normal a few days after & I got a postive opk on aug 25. We did the BD a few times around that time. For the last almost week I have felt so sick, nauseous, esp in the morning. Just like I could puke at anytime. Lots of Heartburn which I never get & I’ve been so thirsty! I have taken a few pregnancy test all negative. I decided to get a first response early detection and took it when I got home around 8. Negative! I don’t know when my period will come since it’s the first after miscarriage.. but I thought maybe in a few days? I also had a few very small spots of blood today like rice size lol I thought I was starting my period but nothing yet. Also noticed maybe I’m getting a UTI (haven’t had one in years, but kinda stings when I pee) I mean if I’m not pregnant, why am I so sick everyday? It’s everything that happened before just no postive test.