Scared, don't know if overreacting

I was supposed to hang out with my boyfriend today because I am leaving the state for about a week and we wanted to hang out while we could. Him and his mom picked me up because he was running errands with her. It was actually really fun- we grabbed breakfast, went to the store, etc. That took about two hours. When we got to his house, I headed up to his room after helping put up groceries and he followed. We were up there for maybe two minutes when his mom called him down and asked me to stay upstairs. I sat there in his room by myself while they talked for maybe ten minutes. Now, his mother knows we are sexually active but I don't know if this is the problem and I don't think it would be as she's known for months. I'm worried that I got him in huge trouble somehow, because when he came upstairs he wouldn't look at me and said he had to take me home and that I needed to go downstairs while he got ready to leave. He wouldn't tell me why and just kissed me on the head before sending me downstairs. On the way to my house he wouldn't talk to me and just said nothing was wrong, but he didn't know if he'd be able to talk to me while I was gone. I'm so confused and so scared and so worried, I can't stop fucking crying. He tells me everything but won't tell me what's wrong and I know he's in trouble. I don't know what to do. I'm scared to text him or message him because I don't know if he has his phone. I don't know what to do. I don't know if I'm overreacting.

edit: he never told me but my sister found out. he used a credit card he found to buy condoms. I'm probably going to break up with him.