Trigger Warning MC

Hi, just wondering how long after an 11 week miscarriage (12.18.23) does hgc stay in your system. I haven’t done blood work recently. I tested and it was negative on digital and clear blue line test and i haven’t had a cycle yet. I’ve tested again recently assuming I ovulated and it was faint positive on six day or sooner and has gotten darker.

Also i’ve done an ultra sound a couple weeks ago and all symptoms have subsided including nothing no longer in my uterus

Pics Monday vs Today

So is this positive real?