Can I be pregnant? What should I do?

Me and my boyfriend have had sex a few time but I get scared every time thinking I am pregnant. The first I did it was December of last year got my normal period cycle in January but it was a few days late and we had sex again in January but my period didn’t come in February but came in March I’m confused but my boyfriend and I had sex about a month ago ( with a condom but it ended up ripping) and I’m scared I can be pregnant and I’m scared to buy a pregnancy test because I’m scared of my mom finding out that I might be pregnant. What should I do?