What should I do

I'm 17 years old. I've been going out with a guy for a few months now and I feel like I am the happiest girl in the world with him. We've been doing more and more sexual things lately and I really badly want to go all the way. I'm pretty sure he does too. But I don't want to do it without protection cause it obviously isn't a good idea but o can't get it from anywhere. My mother always told me to come talk to her before so she can get me some kinda of protection but I'm really scared of what she will say as the relationship is only a month old. Before anyone asks, I do feel ready for it, and I think he is too.