Where is my cervix?

I know this is probably gonna sound crazy...but I can't feel my cervix. I've been tinkering around with cervical position this month......usually i just do Opks.....and my period is due in 7 days and I can't find the damn thing. I can feel when it's low because when my hubby and I have sex it feels like he's punching me. Tonight we did and my vagina felt like it was going on forever...he didn't hit a wall or anything.....

Am I doing something wrong here? I've looked at diagrams and I've reached back its like endless vagina right now