How To Test For Pregnancy?

Recently I took a pregnancy test, which I saw two lines but the second line was really light. I took another one the next day which only had one. I m not to sure what to do. I had a miscarriage last year, I wasn t aware that I was even pregnant. My menstrual cycle is irregular, so I don t know when it s going to come. Could a pregnancy test detect if I was pregnant or is it best I go see my doctor?