BBT??? help!

Hi :) this is my first month properly charting my bbt. Is there a way to tell st this stage if it is normal so far or not? I tried looking at the article on here about different types of thermal shifts but my chart so far doesn't really match ! Also side note the chart shows my fertile window to be CD18-25 but I have just started taking vitex and lots of women say that this has brought their ovulation back to CD14ish, could that dip and then rise be that? :)