Exhausted

Last night I was super tired and didn't want to have sex with my husband which isn't like me and I went to sleep. But today even after I slept i am still tired idk why I have no energy and just want to sleep. According to the app I am supposed to ovulate today and yesterday was my highest chance which not sure how accurate that is because I haven't been doing any opks because we have decided to let it happen when it happens, but could this be tiredness from ovulation or just me simply being exhausted? 0