Could My Pregnancy Test Be Wrong , Am I Pregnant ?

Patient: I lost my virginity 1 month ago using no protection.He used the pull out method .The first time he pulled out he came wiped his penis and went back in .On the day when my period was due i experience a brownish spotting for 2 days and my regular period for 3 days and the same brownish spotting 1 day after .I took a pregnancy test when the spotting stopped and it was negative.2 days after i took another pregnancy test (First response) It was also negative. Can I be pregnant ?