Feel like my boyfriend isn't sexually attracted to me anymore

Jessica
I've been with my boyfriend nearly 4 years, and I'm kind of going through a phase where I could literally have sex everyday it's kind of annoying haha! I don't try anything or ask him all the time but when I do try and start it he pulls away or says not tonight. So in my head I feel like he isnt attracted to me anymore don't know if I'm being stupid? anyone been in this situation before??? :(