21w Pulsing Cervix

It honestly has to be the baby, because it feels like strong kicks, but it may not be. I'm not sure.
It just feels like, if it is him, he's punching and kicking my cervix super low, right at the opening and it is horrifying me.
Can babies get too low? Is this common if it's not the baby kicking? I've been having tons of new symptoms this week and it's all just coming on so fast.