How to tell my mum I’m sexually active ?

I really need some advice on what to do, I’m 15 and I have been with my boyfriend for a while, we have been having sex for about a month. Please don’t leave any comments about the fact I am too young, I understand many people have these views but this is the decision I have made and being told I shouldn’t have won’t help me. I am always extremely safe and we never have sex without a condom. We also always check to condom afterwards to make sure there are no rips. I really want to tell my mum that I am sexually active because I hate lying to her and I would like someone to help me get on the pill and just be able to be open and ask questions if I am worried about anything (for example a late period etc) . I have tried asking for the pill but she just thinks it’s to regulate my period and won’t let me go on it as she says she doesn’t like the fact it’s pumping hormones into my body at such a young age. She has no idea I am sexually active and don’t want her to freak out and never let me see my boyfriend or not speak to me / break the bond I have with her. She has always said to me she would not judge me and would help me get things to keep me safe no matter my age. But now I am in a serious relationship and finally brought it up she just said no way and looked like she was about to cry.

My options are:

Tell her I have been lying to her and be completely honest and risk my relationship

Tell her I’m thinking about becoming sexually active and would like her help to get on the pill “before I have sex”

Or keep it to myself and go get the pill myself/ continue hiding it from her