We [17M & 17F] have just got together and I'm really happy but there are somethings I'm not sure about

We both admitted we liked each other about a month ago but only got together on Friday. I do love her and really like spending time with each other. Yesterday we were making out on my bed and she suggested I kiss her boobs, I did it but on reflection I just feel like it wasn't 'us' and I'd rather take it a bit slower. I told her this last night and I feel like she was really upset. Has anyone got any advice on what to do in this kind of situation.