Could I still be pregnant?

Hi ladies, my husband and I have been trying to get pregnant with our second baby. I am currently 12 dpo and I have taken several tests up until yesterday and all have been negative. My period should start Monday so I’m trying to make myself wait til then to take another one. But I’m so nervous that I’m getting so close to my period and no positive tests, could i still be pregnant and just not show on a test yet?