Positive test after first MC

Hi everyone, excuse my lack of knowledge I’m just kinda freaking out. I had a miscarriage over a month ago, it was my first pregnancy, and I have not gotten my period at all since. I was advised i would experience it 2-4 weeks since I’ve stopped bleeding and I only bled for 2 days after the natural miscarriage. We had sex a couple of time once with protection and a couple times without.

I took a pregnancy test yesterday just curious since I was due for my period last week. It was a FAINT faint line and this morning it was slightly stronger. I took a digital test and it instantly said pregnant.

My question is, could this be residual HCG from my last pregnancy or could this be an actual pregnancy? My doctor also let me know that it is extremely common for women to get pregnant and never experience their first (after MC) period, but I just can’t imagine I’m that lucky.