Could i possibly be pregnant?

i had a miscarriage about a month ago and i was 12 weeks. i have been having unprotected sex lately. i dont have any symptoms of being pregnant i just havnt had my period yet and about 2 weeks ago my dr said that my hormones were down to 45. i took 2 pregnancy test and they both came out positive but faintly. could i be pregnant again or is it from the first pregnancy?