Should I tell my parents I want to start having sex

Me and my boyfriend have talked and we want to start having sex, I have had the talk with my parents of course and my mum said she would prefer me to tell her when I'm going to start so she can provide us with contraceptives such as condoms and get me on the pill however she was implying this for when I was older, say 17/18 whereas i am 15 now so I am unsure if her opinion would change and not be as supportive. I know she would not like me to become sexually active right now as I am a year underage and I know she would not expect it but it's something I feel I am ready to do and excited for. My only fear is that after telling her she wont let me see my boyfriend or she will restrain our time together (for example as of now we are allowed in my bedroom however I am scared she we won't be allowed to each other's houses or have alone time anymore). If I didn't tell my mum the sex would still be safe as my boyfriend has condoms and I can go to a clinic to get on the pill. My mum knows my boyfriend and his family very well but I am unsure of what her reaction would be and don't want it to end up ruining my relationship if she reacts badly