About my sexual desire

Hi, it's 23f, basically it started where I don't feel anything much with my partner while doing it , maybe I'm sliding in my asexual side , i don't feel like doing it or doing it once a week

Is this normal cause I've been living with my partners in livin' relationship from last 2 years and I want to have sex only once a week or don't feel like doing it as I can already predict his moves which doesn't excite me anymore Is this common? Cause I heard couple in my age do it 3-4 times a week.