explaining this to me please help

I don't get periods and I have had them for 3 years. My period ended on the 7th of April. I had sex today without a condom. I think my boyfriend accidentally cummed inside me, but I don't know. Am I going to get pregnant can someone explain if I am going to get pregnant or am I just confused because I seriously don't get periods. Unfortunately my mum passed away so there was nobody to explain it to me and I feel awkward talking to my foster mum... can someone explain it all in the simplest form and tell me if I'm going to be pregnant?