Help, please!

I have missed my period, boobs are aching constantly, exhausted, nauseated etc etc. However I've been checking my cervix and it's gone from high and soft, facing backwards, to now high, firm and facing forwards. I can't tell if it's closed or open and I feel achy. My test have all been negative so far but I'm only 10 days past ovulation. Just wondering if anyone else has experienced such a rapid change in their cervix positioning before.. I am suffering with constipation as well and I know this can affect it sometimes.