Could I be pregnant?

So I’m freaking out. My boyfriend and I had sex for the first time and he used a condom and pulled out. I then got my period two days later. It’s now been around 10 to 12 days since my period finished and I had some very light blood come out. Am I pregnant? I also had and ultrasound 5 days ago but nothing was said can they see pregnancy that early in an ultrasound?