Helllp. Faint positive then negative

I woke up this morning around 10am and had sex with my partner.

I went to the bathroom and wiped and saw some faint blood. Only when I wiped. I reached in my vagina to see if it just wasn't falling out nothing but blood tinged mucus. Within minutes it was gone.

But no period. Havent bled all day.

Thinking maybe implantation bleeding.

So around 3pm I bought a pregnancy test

It came back faint but clearly positive. I had only peed the one time and only had one cup of coffee in between the time I woke up and took the test.

So outta concern I took the second around 845pm. I have also releived my bladder a lot in between.

This one came back negative.

I was suppose to get my period today.

I've also experienced multiple miscarriages and know that hcg wouldnt leave my urine that fast if it indeed was there.

What so I believe?

How do I stay calm?