I need advice

Right so I'm 18 and this wasn't exactly planned I'm now 13 weeks. And I still live with my mum. I felt like I should of had an abortion weeks ago but it changed my mind because maybe it is time for me to have a baby. I feel like I love them already. But I haven't told my mum yet. I'm so scared to. Any advice on telling her? (And there is no father we lost contact after we had sex)