Any advice?!

So me and my boyfriend have been dating for 3 months; however, we’ve been talking for about 6. As soon as we met we both instantly knew we were attracted to one another. He’s my first ever serious relationship so I didn’t jump straight into things but we eventually let things happen on their own. The other night he stayed over and we were home alone and we had sex. It wasn’t really planned it sort of just happened. In the heat of the moment we didn’t use any protection (yes stupid of us) but hey pulled out and we didn’t really worry about anything. I got my period and all but I was just wondering if that is enough to clear the air for me. He also was very relieved when I told him I got my period. As well, I don’t know how to mention to my mother that I want or need to get on birth control because I know that it’ll happen again and I just wanna be safe. Any suggestions? Thank you all in advance!