7 weeks pregnant-low hard cervix

So I have been checking my cervix since before pregnancy. When I first got pregnant it was consistently high and soft. Thursday I had sex with my SO, then Friday and today my cervix is low and hard. I also have dried up and have no CM. I do not feel many symptoms anymore. I was feeling nauseous, fatigue, and sore breasts. Now I just have slightly sore breasts. Is this something to be concerned about? Has anyone has a cervical change in early pregnancy and baby has been fine?