2 days late and still no period

So I just got off my bc last month and my cycle came on right after. After it went off me and my husband had sex 2 times before ovulation and 1 day after. We used the withdrawal method (I know thats not a type of birth control). A week before my period was due I started having cramps and pink spotting off and on. I took a pregnancy test last week but it was negative. Fast forward now I'm 2 days late and still pink spotting here and there but when I put in a tampon there's nothing there? So could I be pregnant or could I be that I just got of my bc and my cycle is not regular yet? I don't want to waste money on another pregnancy test or make a visit to the doctor for no reason.