Guys what would you say if a girl asked you this?

I am 15 years old and had sex with an 18 year old yesterday. I think I could have gotten myself pregnant by him. I had cramps and they went away after I had sex with him. I know he prec*m inside me but not c*m. What would you do if you were 18 years old and was asked my a 15 year old girl that you had sex with knowing it's not legal how would you react if she asked you if you could get her a pregnancy test? I feel like If i miss my period I will be too scared to ask my mom and I don't have money to buy one and I can't leave the house ever by myself so I would have to have a parent there anyways and I feel like if I miss my period I will have to ask for his help with getting a test and I don't know how he would react. I am scared. he is like my best friend ever and I like him and I don't want any awkwardness between us. Please help me :(