Cervex position

I just read taking control of your fertility and they spoke a lot about cervex night and openness. I feel like mine is always the same, I have to go deep and I always feel like a bump. Should it be a drastic change ? I feel like in the book it makes it seem like the day after you ovulate you should be so low that you can barely put a finger in. Most days for me I have to do in deep and find it. I got a positive opk on the 26th and I still feel like a have to venture far to feel it. Any suggestions