February/ HCG/ positive test

Complicated question for a overthink TTC momma with anxiety due to miscarriages.

We miscarried in October. Yesterday, I got a faint line test and today also tested positive. I called my doctor right away to get a HCG count, however, my HCG was only 4.

Could the shorter month have an effect on this? My cycle is usually a 31 day cycle and my period is typically at the very end of the month. My first day of my LMS was January 26th with ovulation on February 10th/11th ish.