Chemical? PLEASE read

My period is due Thursday or Friday.

I took a test Sunday night it was a faint faint positive with first response

I took another Monday morning it was darker and clearly positive but faint still

I took another Monday night and it was there still about the same shade with a different test

I took one this morning, the line was even fainter but there

I took 4 about 20 minutes ago and it’s negative...

I’ve had 4 miscarriages and now probably a chemical.. :(