Faint Lines

I had a missed miscarriage at 6.5 weeks (was getting my 12 week scan done when they noticed) and had surgery to remove in October, had normal period October. November I got faint positives that didn’t develop. It has also happened this month. A faint positive (strong enough for us to see it well) and then since then they’ve gotten lighter. I’m 5 days out from my period. Has anyone experienced anything similar before? Picture is of my positive from 4 days ago, since then i had very faint lines and then today it was gone.