being in love but not wanting sex all of the time

Is it normal to not want sex all of the time? Im 18 and a female, and my boyfriend and I have had sex three times in our four month relationship. I love him so much, and I know he loves me too, but is there something wrong with me for not wanting sex alot? I just thought of it now, and I dont know if that means i'm losing feelings or not because I think im just getting more feelings for him as our relationship progresses. Hes already told me that he plans on marrying me, and being with me for the rest of my life. Even told my parents this. I just get scared if im getting too comfortable by not having sex more or not. Please, any tips would be great.