Why do I feel so guilty?!

G

So I’m 15 and I lost my virginity a few weeks ago before my birthday to the boy I love. We’ve been dating for a while now, almost five months. And he’s so so so good to me. He’s such a gentleman and I know that I made the right choice. Part of me wishes I waited but part of me also is happy we took that step. But now I feel guilty about it, my mom found out a few days after and she was upset but I wrote her a letter and she seemed to get over it. Yesterday I ordered condoms on amazon because you know, better safe than sorry. But I’m worried my mom will see the package and question it. For some reason I feel guilty about that and I don’t know why, because if you’re going to do it you should at least be responsible. And I am. But I seem to go through phases of guilt and happiness over the subject. Is this bad?